Novel Ethylene Copolymers, Compositions Comprising Same and Preparation and Treatment Methods

ABSTRACT

The invention concerns novel ethylene copolymers comprising polyethylene glycol (meth)acrylate monomers, cationic monomers, and optionally amphoteric, anionic and/or hydrophilic nonionic monomers, neutralized by particular neutralizing agents. The invention also concerns composition in particular cosmetic or pharmaceutical comprising said copolymers, as well as methods for preparing said copolymers, and cosmetic treatment methods using same.

The present invention relates to novel polymers, to their use especially in cosmetics, and to compositions comprising them.

It is known practice to use polymers in cosmetics, and especially in haircare, for example to give the hair hold or body. In the field of “rinse-out” hair compositions, such as shampoos or hair conditioners, water-soluble synthetic cationic polymers are especially used, which are known to give the hair good cosmetic properties; however, these polymers do not provide any hair shaping effect. This is likewise the case for cationic polymers of natural origin such as modified guars, which also provide a cosmetic nature without allowing hair shaping. Compositions that afford styling and that have an acceptable cosmetic nature are not known in the field of rinse-out compositions. In the field of “leave-in” hair compositions, such as styling products of the styling lacquer, gel or spray type, there is an ongoing search for polymers that give the hair styling effects and hold. Polymers containing amine units, such as polymers based on vinylpyrrolidone and dimethylaminoethyl methacrylate (Gaffix polymers) are known in styling products. However, the compositions obtained have insufficient hold over time. Polymers of Luviquat type, based on quaternized vinylimidazole and vinylpyrrolidone, are also known, and provide softness, but thicken the compositions.

The aim of the present invention is to propose polymers capable of providing a real styling effect while at the same time conserving an acceptable cosmetic nature for compositions, and especially sparingly viscous polymers that only slightly modify the viscosity of the compositions comprising them. After considerable research, the Applicant has demonstrated that the use of polymers comprising, inter alia, monomers of the polyethylene glycol (meth)acrylate type as defined below, can allow the preparation of styling compositions with an adequate cosmetic nature.

Polymers containing polyethylene glycol (meth)acrylate (MPEG) units are described in the prior art.

Thus, EP 372 546 discloses copolymers based on MPEG and monomers of C1-C8 alkyl (meth)acrylamide type, which may comprise cationic monomers. However, these polymers comprise only a small proportion of cationic monomers, which does not allow them to generate adequate cosmetic effects, especially deposition on the hair that is sufficient to provide the desired properties.

It is to the Applicant's credit to have noticed that it is preferable to use polymers comprising high cationic charge contents in order to obtain a satisfactory deposit of said polymer on the hair.

Document JP2002-322 219 describes polymers containing MPEG units in combination with hydrophobic monomers based on polypropylene glycol (PPO) or polytetramethylene oxide, and cationic monomers. However, it has been found that these polymers comprising hydrophobic monomers do not allow satisfactory cosmetic properties to be obtained.

A composition comprising cationic polymers in which the monomers of PEG type are combined with monomers comprising quaternary amine units is also known from patent JP2002-284 627. However, the presence of quaternary units may induce, gradually in the course of applications, extra deposition that may, in certain cases, harm the cosmetic quality of the composition. Moreover, these polymers contain a low content of cationic charge, of about 0.5% to 6%, which does not allow optimum affinity for the hair.

JP2003-055 164 also discloses polymers containing units of MPEG type; however, these polymers are crosslinked, which makes controlling their synthesis difficult.

Document JP2000-302 649 describes a haircare composition comprising a polymer that comprises cationic or amphoteric monomers, monomers with a polyether group, especially of PEG or PPO type, and also optional monomers that may be mainly hydrophobic (for example stearyl methacrylate).

Haircare compositions comprising a polymer that comprises monomers of MPEG type in combination with ionic, cationic or amphoteric monomers, and additional monomers of C1-C24 alkyl (meth)acrylate type, which are mainly hydrophobic, are also known from patent JP07-285 831.

However, the presence of hydrophobic comonomers, for example of butyl or stearyl acrylate type, does not make it possible to obtain adequate cosmetic properties, and especially does not make it possible to obtain good disentangling of wet hair, just after shampooing.

Patent application WO 03/075 867 is also known, which describes linear block copolymers comprising a poly(alkylene glycol) block surrounded by two ethylenic blocks. These polymers have the drawback of having a central block of poly(alkylene glycol) type of high mass, which gives the polymer high crystallinity, which may lead to opaque products and/or products of greasy nature.

The Applicant has discovered novel polymers that can give a styling and conditioning effect to cosmetic haircare products.

Surprisingly, the polymers according to the invention have advantageous cosmetic properties, for example during application in a formulation of shampoo type; specifically, it has been found that the hair disentangles easily during shampooing, and/or when the hair is still wet; moreover, the hair is soft; after drying, the compositions according to the invention also allow, once the hair has dried, particularly advantageous shaping of the hair.

Without wishing to be bound by the present explanation, it may be considered that this may be due especially to the presence of PEG (meth)acrylate (MPEG) units in the polymer chain, these units largely contributing to the obtained effect. Specifically, it has been found that this effect is not obtained with a simple mixture of cationic polymer and of polymer of PEG type.

These effects may also be associated with the fact that the cationic units of the polymer are neutralized, and even more particularly with the fact that they are neutralized with a neutralizer of organic nature.

One subject of the present invention is thus an ethylenic copolymer comprising, as a weight percentage relative to the total weight of the polymer:

-   -   a) 10-80% by weight of one or more monomers of formula (I) as         defined below;     -   b) 20-90% by weight of at least one cationic monomer, or a salt         thereof, chosen from the monomers of formula (IIa) as defined         below;         said copolymer being at least partially neutralized with at         least one neutralizer chosen from organic acids in the Brönsted         sense.

Another subject of the invention is a composition comprising, in a physiologically acceptable medium, at least one such copolymer.

Yet another subject of the invention is a process for preparing said ethylenic copolymer, in which the amine units of the monomers included in the constitution of the polymer, in particular the amine units of the cationic monomers of formula (IIa), are neutralized before their polymerization, and the neutralized monomers are then copolymerized in order to obtain the desired copolymer.

Yet another subject of the invention is a process for preparing said ethylenic copolymer, in which the non-neutralized monomers included in the constitution of the copolymer are copolymerized, and said copolymer is then neutralized after its formation.

The polymers according to the invention thus afford good cosmetic properties, especially disentangling and/or smoothing, in particular when the hair is wet, but also when the hair is dry. These polymers also give the hair softness.

Moreover, the present invention has the advantage of proposing polymers that are generally conveyable in water, i.e. water-soluble or water-dispersible, which allows them to be used advantageously in cosmetic compositions, especially for skincare or haircare, which are generally water-based.

The term “water-soluble” means that the polymer forms a clear solution in water, in a proportion of at least 5% by weight, at 25° C.

The term “water-dispersible” means that the polymer forms in water, at a concentration of 5% by weight, at 25° C., a stable suspension or dispersion of fine, generally spherical particles. The mean size of the particles constituting said dispersion is less than 1 μm and more generally ranges between 5 and 400 nm and preferably from 10 to 250 nm. These particles sizes are measured by light scattering.

In the rest of the present description, the term “cyclic radical” means a monocyclic or polycyclic radical, which may be in the form of one or more saturated and/or unsaturated, optionally substituted rings (for example cyclohexyl, cyclodecyl, benzyl or fluorenyl), but also a radical that comprises one or more of said rings (for example p-tert-butylcyclohexyl or 4-hydroxybenzyl).

The term “saturated and/or unsaturated radical” means totally saturated radicals, totally unsaturated radicals, including aromatic radicals, and also radicals comprising one or more double and/or triple bonds, the rest of the bonds being single bonds.

The ethylenic copolymer according to the invention thus comprises at least one monomer of formula (I), which may be present alone or as a mixture:

in which:

-   -   R1 is a hydrogen atom or a linear or branched hydrocarbon-based         radical, of the type C_(p)H_(2p+1), with p being an integer         between 1 and 12 inclusive;     -   Z is a divalent group chosen from —COO—, —CONH—, —CONCH₃—,         —OCO—, —O—, —SO₂—, —CO—O—CO— and —CO—CH₂—CO—;     -   x is 0 or 1;     -   R2 is a saturated or unsaturated, optionally aromatic, linear,         branched or cyclic carbon-based divalent radical of 1 to 30         carbon atoms, possibly comprising 1 to 18 heteroatoms chosen         from O, N, S, F, Si and P;     -   m is 0 or 1;     -   n is an integer between 3 and 300 inclusive;     -   R3 is a hydrogen atom or a saturated or unsaturated, optionally         aromatic, linear, branched or cyclic carbon-based radical of 1         to 30 carbon atoms, possibly comprising 1 to 20 heteroatoms         chosen from O, N, S, F, Si and P;         and salts thereof.

R1 may especially represent a methyl, ethyl, propyl or butyl radical. Preferably R1 represents hydrogen or a methyl radical.

Preferably, Z represents COO or CONH.

Preferably, x is equal to 1.

In the radical R2, the heteroatom(s), when they are present, may be intercalated in the chain of said radical R2, or alternatively said radical R2 may be substituted with one or more groups comprising them such as hydroxy or amino (NH2, NHR′ or NR′R″ with R′ and R″, which may be identical or different, representing a linear or branched C1-C22 alkyl, especially methyl or ethyl).

R2 may especially be:

-   -   an alkylene radical such as methylene, ethylene, propylene,         n-butylene, isobutylene, tert-butylene, n-hexylene, n-octylene,         n-dodecylene, n-octadecylene, n-tetradecylene or n-docosanylene;     -   a phenylene radical —C₆H₄— (ortho, meta or para) optionally         substituted with a C1-C12 alkyl radical optionally comprising 1         to 25 heteroatoms chosen from O, N, S, F, Si and P; or         alternatively a benzylene radical —C₆H₄—CH₂—, optionally         substituted with a C1-C12 alkyl radical optionally comprising 1         to 8 heteroatoms chosen from O, N, S, F, Si and P;     -   a pyridinium radical of formula:

with R′1 to R′4, which may be identical or different, chosen from H and a C1-C12 alkyl radical optionally comprising 1 to 8 heteroatoms chosen from O, N, S, F, Si and P; R′1 to R′4 may especially be methyl and/or ethyl;

-   -   a radical of formula —CH₂—O—CO—O—, CH₂—CH₂—O—CO—O—, —CH₂—CO—O—,         —CH₂—CH₂—CO—O—, —CH₂—O—CO—NH—, —CH₂—CH₂—O—CO—NH—;         —CH₂—NH—CO—NH—, —CH₂—CH₂—NH—CO—NH—; —CH₂—CHOH—, —CH₂—CH₂—CHOH—,         —CH₂—CH₂—CH(NH₂)—, —CH₂—CH(NH₂)—CH₂—CH₂—CH(NHR′)—,         —CH₂—CH(NHR′)—, —CH₂—CH₂—CH(NR′R″)—, —CH₂—CH(NR′R″)—,         —CH₂—CH₂—CH₂—NR′—, —CH₂—CH₂—CH₂—O—; —CH₂—CH₂—CHR′—O— with R′ and         R″ representing a linear or branched C1-C22 alkyl optionally         comprising 1 to 12 heteroatoms chosen from O, N, S, F, Si and P;     -   or a mixture of these radicals.

Preferably, n is between 5 and 200 inclusive and better still between 7 and 100 inclusive, or even between 9 and 50 inclusive.

Preferably, R3 is a hydrogen atom; a benzyl or phenyl radical optionally substituted with a C1-C12 alkyl radical optionally comprising 1 to 8 heteroatoms chosen from O, N, S, F, Si and P; a C1-C30 and especially C1-C22 or even C2-C16 alkyl radical, optionally comprising 1 to 18 heteroatoms chosen from O, N, S, F, Si and P.

These benzyl, phenyl or alkyl radicals may especially comprise a function chosen from the following functions:

or alternatively chosen from —SO₃H, —COOH, —PO₄, —NRSR6 and —N⁺R5R6R7, with R5, R6 and R7, independently of each other, chosen from H and linear, branched or cyclic C1-C18 alkyls, especially methyl optionally comprising one or more heteroatoms or alternatively bearing protective groups such as t-butyloxycarbonyl (also known as BOC) or 9-fluorenylmethoxycarbonyl (also known as Fmoc).

Among the radicals R3, mention may be made of methyl, ethyl, propyl, benzyl, ethylhexyl, lauryl, stearyl and behenyl (—(CH₂)₂₁—CH₃) chains, and also fluoroalkyl chains, for instance heptadecafluorooctylsulfonyl-aminoethyl CF₃— (CF₂)₇—SO₂—N(C₂H₅)—CH₂—CH₂; or alternatively —CH₂—CH₂—CN, succinimido, maleimido, mesityl, tosyl, triethoxysilane or phthalimide chains.

The possible amine units of monomer of formula (I) may optionally be neutralized, in the manner described later.

Among the monomers of formula (I) that are particularly preferred, mention may be made of:

-   -   poly(ethylene glycol) (meth)acrylate in which R1 is H or methyl;         Z is COO, x=1, m=0 and R3=H;     -   methylpoly(ethylene glycol) (meth)acrylate, also known as         methoxypoly(ethylene glycol) (meth)acrylate, in which R1 is H or         methyl, Z is COO, x=1, m=0 and R3=methyl;     -   alkylpoly(ethylene glycol) (meth)acrylates in which R1 is H or         methyl, Z is COO, x=1, m=0 and R3=alkyl;     -   phenylpoly(ethylene glycol) (meth)acrylate, also known as         poly(ethylene glycol) phenyl ether (meth)acrylate, in which R1         is H or methyl, Z is COO, x=1, m=0 and R3=phenyl;     -   the following monomer:

in which n is preferably between 3 and 100 inclusive and especially 5 to 50 inclusive, or even 7 to 30 inclusive.

Preferably, the monomer of formula (I) has a molecular weight of between 350 and 13000 g/mol and especially between 500 and 8000 g/mol.

The monomers of formula (I) that are most particularly preferred are chosen from poly(ethylene glycol) (meth)acrylates and methylpoly(ethylene glycol) (meth)acrylates, preferably those with a molecular weight of between 350 and 13000 g/mol and especially between 500 and 8000 g/mol.

Poly(ethylene glycol) (meth)acrylates are most particularly preferred, and in particular those with a molecular weight of between 350 and 13000 g/mol and especially between 500 and 8000 g/mol.

EXAMPLES OF COMMERCIAL MONOMERS ARE

-   -   CD 350 (methoxypoly(ethylene glycol 350) methacrylate) and CD         550 (methoxypoly(ethylene glycol 550) methacrylate), sold by         Sartomer Chemicals;     -   M90G (methoxypolyethylene glycol methacrylate (9 repeating         units)) and M230G (methoxypolyethylene glycol methacrylate (23         repeating units)) available from Shin-Nakamura Chemicals;     -   methoxypoly(ethylene glycol) methacrylates with average         molecular weights of 300, 475 or 1100, available from         Sigma-Aldrich;     -   methoxypoly(ethylene glycol)acrylate with an average molecular         weight of 426, available from Sigma-Aldrich;     -   methoxypoly(ethylene glycol) methacrylates available from         Laporte under the trade names: MPEG-350, MPEG 550, S10W, S20W;     -   poly(ethylene glycol) monomethyl ether, mono(succinimidyl         succinate) ester with an average molecular weight of 1900 or         5000, from Polysciences;     -   behenylpoly(ethylene glycol PEG-25) methacrylate, available from         Rhodia under the name Sipomer BEM;     -   poly(ethylene glycol)phenyl ether acrylates with average         molecular weights of 236, 280 or 324, available from Aldrich;     -   methoxypolyethylene glycol 5000 2-(vinylsulfonyl)ethyl ether         available commercially from Fluka;     -   polyethylene glycol ethyl ether methacrylate available from         Aldrich;     -   polyethylene glycol 8000, 4000, 2000 methacrylates from Monomer         & Polymer Dajac Laboratories;     -   polyethylene glycol N-hydroxysuccinimide vinyl sulfone available         commercially from Nektar Molecule Engineering (Shearwater).

The monomer of formula (I), alone or as a mixture, is present in a proportion of from 10% to 80% by weight, especially from 20% to 60% by weight and preferably from 30% to 50% by weight relative to the weight of the final polymer.

The ethylenic copolymer according to the invention also comprises at least one cationic monomer, or a salt thereof, chosen from the monomers of formula (IIa).

It may also comprise one or more additional ionic monomers chosen from the amphoteric monomers of formulae (IIc) and (IId), and/or anionic monomers chosen from maleic anhydride and/or those of formula (IIb).

The term “cationic monomer” means monomer comprising units capable of bearing a cationic charge in the pH range of between 3 and 12. These units do not necessarily have a permanent charge irrespective of the pH. The cationic unit does not need to be protonated at each of these pH values.

The cationic monomer, or a salt thereof, is thus chosen from the monomers of formula (IIa):

in which:

-   -   R1 is a hydrogen atom or a linear or branched hydrocarbon-based         radical of the type C_(p)H_(2p+1), with p being an integer         between 1 and 12 inclusive.

R1 may especially represent a methyl, ethyl, propyl, or butyl radical. Preferably, R1 represents hydrogen or a methyl radical.

-   -   Z′ is a divalent group chosen from —COO—, —CONH—, —CONCH₃—,         —OCO— or —O—, —SO₂—-CO—O—CO— or —CO—CH₂—CO—.

Preferably, Z′ is chosen from COO and CONH.

-   -   x′ is 0 or 1, preferably 1.     -   R′2 is a saturated or unsaturated, optionally aromatic, linear,         branched or cyclic divalent carbon-based radical of 1 to 30         carbon atoms, possibly comprising 1 to 18 heteroatoms chosen         from O, N, S, F, Si and P.

In the radical R′2, the heteroatom(s), when they are present, may be intercalated in the chain of said radical R′2, or alternatively said radical R′2 may be substituted with one or more groups comprising them such as hydroxyl or amino (NH2, NHR′ or NR′R″ with R′ and R″, which may be identical or different, representing a linear or branched C1-C22 alkyl, especially methyl or ethyl).

R′2 may especially be:

-   -   an alkylene radical such as methylene, ethylene, propylene,         n-butylene, isobutylene, tert-butylene, n-hexylene, n-octylene,         n-dodecylene, n-octadecylene, n-tetradecylene or n-docosanylene;     -   a phenylene radical —C₆H₄— (ortho, meta or para), optionally         substituted with a C1-C12 alkyl radical optionally comprising 1         to 25 heteroatoms chosen from N, O, S, F, Si and/or P; or         alternatively a benzylene radical —C₆H₄—CH₂—, optionally         substituted with a C1-C12 alkyl radical optionally comprising 1         to 25 heteroatoms chosen from O, N, S, F, Si and P;     -   a radical of formula —CH₂—O—CO—O—, CH₂—CH₂—O—CO—O—, —CH₂—CO—O—,         —CH₂—CH₂—CO—O—, —[(CH₂)₅—CO—O]_(n)—, —CH₂—CH(CH₃)—O—,         —(CH₂)₂—O—, —CH₂—O—CO—NH—, —CH₂—CH₂—O—CO—NH—; —CH₂—NH—CO—NH— or         —CH₂—CH₂—NH—CO—NH—, —CH₂—CHOH—, —CH₂—CH₂—CHOH—,         —CH₂—CH₂—CH(NH₂)—, —CH₂—CH(NH₂)—, —CH₂—CH₂—CH(NHR′)—,         —CH₂—CH(NHR′)—, —CH₂—CH₂—CH(NR′R″)—, —CH₂—CH(NR′R″)—,         —CH₂—CH₂—CH₂—NR′—, —CH₂—CH₂—CH₂—O—; —CH₂—CH₂—CHR′—O— with R′ and         R″ representing a linear or branched C1-C22 alkyl optionally         comprising 1 to 12 heteroatoms chosen from O, N, S, F, Si and P;     -   or a mixture of these radicals;     -   m′ is 0 or 1;     -   X is a guanidino or amidino group, or a group of formula         —N(R₆)(R₇) or —P(R₆)(R₇) or —P⁺R₆R₇R₈, with R₆, R₇ and R8         representing, independently of each other, either (i) a hydrogen         atom, or (ii) a linear, branched or cyclic, saturated or         unsaturated, optionally aromatic alkyl group containing from 1         to 18 carbon atoms, possibly comprising 1 to 10 heteroatoms         chosen from O, N, S, F, Si and P; or (iii) R6 and R7 may form         with the nitrogen or phosphorus atom a first saturated or         unsaturated, optionally aromatic ring comprising in total 5, 6,         7 or 8 atoms, and especially 4, 5 or 6 carbon atoms and/or 2 to         4 heteroatoms chosen from O, S and N; said first ring possibly         being fused with one or more other saturated or unsaturated,         optionally aromatic rings each comprising 5, 6 or 7 atoms, and         especially 4, 5, 6 or 7 carbon atoms and/or 2 to 4 heteroatoms         chosen from O, S and N.

For example, R6 and R7 may be chosen from hydrogen and a methyl, ethyl, propyl, isopropyl, n-butyl, t-butyl, isobutyl, octyl, lauryl or stearyl group.

Preferably, R6 and R7 are chosen, independently of each other, from H, CH3 and C2H5.

Alternatively, X may represent a group —R′6—N—R′7— in which R′6 and R′7 form with the nitrogen atom a saturated or unsaturated, optionally aromatic ring comprising in total 5, 6, 7 or 8 atoms, and especially 4, 5 or 6 carbon atoms and/or 2 to 4 heteroatoms chosen from O, S and N; said ring possibly being fused with one or more other saturated or unsaturated, optionally aromatic rings, each comprising 5, 6 or 7 atoms, and especially 4, 5, 6, 7 or 8 carbon atoms and/or 2 to 4 heteroatoms chosen from O, S and N.

For example, X may constitute an aromatic or nonaromatic ring comprising a tertiary amine group or may represent an aromatic or nonaromatic heterocycle containing a tertiary nitrogen.

Among these preferred radicals X, mention may be made of radicals of pyridine, indolyl, isoindolinyl, imidazolyl, imidazolinyl, piperidyl, pyrazolinyl, pyrazolyl, quinoline, pyrazolinyl, pyridyl, piperazinyl, pyrrolidinyl, quinidinyl, thiazolinyl, morpholine, guanidino or amidino type, and mixtures thereof.

The guanidino and amidino groups are, respectively, of formula:

The cationic units (amines) of the monomer of formula (IIa) may optionally be neutralized at this stage, in the manner described later.

Among the preferred monomers of formula (IIa) that may be mentioned are:

Among the monomers of formula (IIa) that are particularly preferred, mention may be made of dimethylaminopropyl(meth)acrylamide, dimethylamino-ethyl(meth)acrylamide, diethylaminoethyl (meth)acryl-ate, dimethylaminoethyl (meth)acrylate, vinylimidazole, vinylpyridine and morpholinoethyl (meth)acrylate, and mixtures thereof.

Needless to say, the copolymer may comprise a mixture of various cationic monomers of formula (IIa).

The cationic monomers of formula (IIa) are preferably present in a proportion of from 20% to 90% by weight, especially from 40% to 80% by weight and preferably from 50% to 70% by weight relative to the weight of the final polymer.

The ethylenic copolymer may also comprise at least one additional ionic monomer, chosen from the amphoteric monomers of formulae (IIc) and (IId), and/or anionic monomers chosen from maleic anhydride and/or those of formula (IIb):

in which:

-   -   R1, Z′, x′, R′2 and m′ have the same meaning as that given above         for formula (IIa);     -   Y is a group chosen from —COOH, —SO₃H, —OSO₃H, —PO₃H₂ and         —OPO₃H₂. It is understood that, according to the prior art, the         groups SO₄H₂ and PO₃H are linked to R′2 via the S and P atoms,         respectively.     -   X′⁺ is a divalent group of formula —N⁺(R₆)(R₇)— with R6 and R7         representing, independently of each other, either (i) a hydrogen         atom, or (ii) a linear, branched or cyclic, optionally aromatic         alkyl group containing from 1 to 25 carbon atoms, possibly         comprising 1 to 20 heteroatoms chosen from O, N, S and P;         or (iii) R6 and R7 may form with the nitrogen atom a first         saturated or unsaturated, optionally aromatic ring comprising in         total 5, 6, 7 or 8 atoms, and especially 4, 5, 6 or 7 carbon         atoms and/or 2 to 3 heteroatoms chosen from O, S and N; said         first ring possibly being fused with one or more other saturated         or unsaturated, optionally aromatic rings, each comprising 5, 6,         7 or 8 atoms, and especially 4, 5, 6 or 7 carbon atoms and/or 2         to 3 heteroatoms chosen from O, S and N.

For example, R6 and R7 may be chosen from hydrogen and a methyl, ethyl, propyl, isopropyl, n-butyl, t-butyl or isobutyl group.

Among the preferred radicals X′⁺ that may be mentioned are radicals of pyridine, indolyl, isoindolinyl, imidazolyl, imidazolinyl, piperidyl, pyrazolinyl, pyrazolyl, quinoline, pyrazolinyl, pyridyl, piperazinyl, pyrrolidinyl, quinidinyl, thiazolinyl, morpholine, guanidino or amidino type, and mixtures thereof.

-   -   Y′⁻ is a group chosen from —COO⁻, —SO₃ ⁻, —OSO₃ ⁻, —PO₃ ²⁻ and         —OPO₃ ²⁻.     -   R′3 is a saturated or unsaturated, optionally aromatic, linear,         branched or cyclic divalent carbon-based radical of 1 to 30         carbon atoms, possibly comprising 1 to 18 heteroatoms chosen         from O, N, S, F, Si and P.

In the radical R′3, the heteroatom(s), when they are present, may be intercalated in the chain of said radical R′3, or alternatively said radical R′3 may be substituted with one or more groups comprising them such as hydroxyl or amino (NH₂, NHR′ or NR′R″ with R′ and R″, which may be identical or different, representing a linear or branched C1-C18 alkyl, especially methyl or ethyl).

R′3 may especially be:

-   -   an alkylene radical such as methylene, ethylene, propylene,         n-butylene, isobutylene, tert-butylene, n-hexylene, n-octylene,         n-dodecylene, n-octadecylene, n-tetradecylene or n-docosanylene;     -   a phenylene radical —C₆H₄— (ortho, meta or para), optionally         substituted with a C1-C12 alkyl radical optionally comprising 1         to 5 heteroatoms chosen from O, N, S, F, Si and P; or         alternatively a benzylene radical —C₆H₄—CH₂—, optionally         substituted with a C1-C12 alkyl radical optionally comprising 1         to 5 heteroatoms chosen from O, N, S, F, Si and P;     -   a radical of formula —CH₂—O—CO—O—, CH₂—CH₂—O—CO—O—, —CH₂—CO—O—,         —CH₂—CH₂—CO—O—, [(CH₂)₅—CO—O]_(n)—, —CH₂—CH(CH₃)—O—, —(CH₂)₂—O—,         —CH₂—O—CO—NH—, —CH₂—CH₂—O—CO—NH—; —CH₂—NH—CO—NH— or         —CH₂—CH₂—NH—CO—NH—, —CH₂—CHOH—, —CH₂—CH₂—CHOH—,         —CH₂—CH₂—OH(NH₂)—, —CH₂—CH(NH₂)—, —CH₂—CH₂—CH(NHR′)—,         —CH₂—CH(NHR′)—, —CH₂—CH₂—CH(NR′R″)—, —CH₂—CH(NR′R″)—,         —CH₂—CH₂—CH₂—NR′—, —CH₂—CH₂—CH₂—O—; —[CH₂—CH₂—O]_(n)— and         —[CH₂—CH(CH₃)—O]_(n)—, —CH₂—CH₂—CHR′—O— with R′ and R″         representing a linear or branched C1-C22 alkyl optionally         comprising 1 to 12 heteroatoms chosen from O, N, S, F, Si and P;     -   or a mixture of these radicals;     -   n′ is between 1 and 100 and preferably between 1 and 5         inclusive.     -   X′⁺ is a group of formula —N⁺R₆R₇R₈ with R6, R7 and R8         representing, independently of each other, either (i) a hydrogen         atom, or (ii) a linear, branched or cyclic, optionally aromatic         alkyl group containing from 1 to 18 carbon atoms, possibly         comprising 1 to 5 heteroatoms chosen from O, N, S and P;         or (iii) R6 and R7 may form with the nitrogen atom a first         saturated or unsaturated, optionally aromatic ring comprising in         total 5, 6 or 7 atoms, and especially 4, 5 or 6 carbon atoms         and/or 2 to 3 heteroatoms chosen from O, S and N; said first         ring possibly being fused with one or more other saturated or         unsaturated, optionally aromatic rings, each comprising 5, 6 or         7 atoms, and especially 4, 5, 6 or 7 carbon atoms and/or 2 to 3         heteroatoms chosen from O, S and N.

For example, R6, R7 and R8 may be chosen from hydrogen and a methyl, ethyl, propyl, isopropyl, n-butyl, t-butyl, isobutyl, octyl, lauryl or stearyl group.

Among the preferred radicals X″⁺ that may be mentioned are trimethylammonium; triethylammonium; N,N-di-methyl-N-octylammonium; N,N-dimethyl-N-laurylammonium radicals.

Among the preferred anionic monomers that may be mentioned are maleic anhydride, acrylic acid, methacrylic acid, crotonic acid, itaconic acid, fumaric acid, maleic acid, 2-carboxyethyl acrylate (CH₂═CH—C(O)—O—(CH₂)₂—COOH); styrenesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, vinylbenzoic acid, vinylphosphoric acid and sulfopropyl (meth)acrylate, and salts thereof.

Among the preferred monomers of formula (IIc) or (IId) that may be mentioned are N,N-dimethyl-N-(2-methacryloyloxyethyl)-N-(3-sulfopropyl)ammonium betaine (especially SPE from the company Raschig); N,N-dimethyl-N-(3-methacrylamidopropyl)-N-(3-sulfopropyl)-ammonium betaine (SPP from Raschig) and 1-(3-sulfopropyl)-2-vinylpyridinium betaine (SPV from Raschig), and also 2-methacryloyloxyethylphosphoryl-choline.

Needless to say, the copolymer may comprise a mixture of various additional ionic monomers.

When the copolymer comprises an additional ionic monomer, or a mixture of additional ionic monomers, said additional ionic monomers are preferably present in a proportion of from 5% to 40% by weight, especially from 10% to 30% by weight and preferably from 15% to 25% by weight relative to the weight of the “additional cationic+ionic monomers” mixture.

The ionic monomer(s), i.e. the cationic monomer(s)+the optional additional ionic monomer(s), are preferably present in a proportion of from 20% to 90% by weight, especially from 40% to 80% by weight and preferably from 50% to 70% by weight relative to the weight of the final polymer.

Preferably, the polymer according to the invention comprises the monomers of formula (I) and the ionic monomers (the cationic monomers+the optional amphoteric and anionic monomers) in a weight ratio that may range from 60/40 to 40/60, with a preference for a 50/50 ratio.

The ethylenic copolymer according to the invention may also optionally comprise additional nonionic monomers. When it comprises additional nonionic monomers, they are preferably chosen from the monomers that are “hydrophilic” within the meaning of the present invention.

In the present description, the term “hydrophilic monomer” means monomers with a value of the logarithm of the 1-octanol/water apparent partition coefficient, also known as the log P, of less than or equal to 2, for example between −8 and 2, preferably less than or equal to 1.5, especially less than or equal to 1 and in particular between −7 and 1, or even between −6 and 0.

The log P values are known and determined according to a standard test that determines the concentration of the monomer in 1-octanol and water.

The values may especially be calculated using the ACD software (Advanced Chemistry Development) software Solaris V4.67; they may also be obtained from Exploring QSAR: hydrophobic, electronic and stearic constants (ACS professional reference book, 1995). A website also exists that provides estimated values (address: http://esc.syrres.com/interkow/kowdemo.htm).

The log P value of certain common monomers, determined using the ACD software, are given below:

Methacrylate Acrylate (* or methacrylamide) (* or acrylamide) Methyl (meth)acrylate 1.346 +/− 0.250 0.793 +/− 0.223 Ethyl (meth)acrylate 1.877 +/− 0.250 1.325 +/− 0.223 Propyl (meth)acrylate 2.408 +/− 0.250 1.856 +/− 0.223 Isopropyl (meth)acrylate 2.224 +/− 0.254 1.672 +/− 0.228 Butyl (meth)acrylate 2.940 +/− 0.250 2.387 +/− 0.223 Isobutyl (meth)acrylate 2.756 +/− 0.254 2.208 +/− 0.228 Tert-butyl (meth)acrylate 2.574 +/− 0.261 2.022 +/− 0.238 Cyclohexyl (meth)acrylate 3.405 +/− 0.252 2.853 +/− 0.226 Octyl (meth)acrylate 5.065 +/− 0.521 4.513 +/− 0.224 Lauryl (meth)acrylate 7.190 +/− 0.251 6.638 +/− 0.224 Tridecyl (meth)acrylate 7.712 +/− 0.251 7.170 +/− 0.224 Cetyl (meth)acrylate 9.316 +/− 0.251 8.764 +/− 0.224 Palmityl (meth)acrylate >9 >9 Stearyl (meth)acrylate 10.379 +/− 0.251  9.826 +/− 0.224 Behenyl (meth)acrylate 11.952 +/− 0.225  12.504 ± 0.251  Oleyl (meth)acrylate >9 9.308 ± 0.232 Tetrahydrofurfuryl 1.352 ± 0.283 0.800 ± 0.263 (meth)acrylate 2-Ethyl hexyl 4.881 ± 0.254 4.329 ± 0.229 (meth)acrylate 2-Hydroxyethyl 0.718 ± 0.277 0.166 ± 0.258 (meth)acrylate Ethoxyethyl 1.887 ± 0.293 1.335 ± 0.268 (meth)acrylate Hydroxypropyl 0.383 ± 0.241 (meth)acrylate N-isopropyl 0.748 ± 0.276 0.195 ± 0.256 (meth)acrylamide* N-octyl (meth)acrylamide* 3.558 ± 0.273 3.036 ± 0.253 N,N-dimethyl 0.906 ± 0.553 −0.168 ± 0.556  (meth)acrylamide* N,N-dibutyl 3.573 ± 0.570 3.021 ± 0.557 (meth)acrylamide* Vinyl acetate 0.730 ± 0.286 Methyl vinyl ether 0.509 ± 0.286 Ethyl vinyl ether 1.040 ± 0.286 Vinylcaprolactam 1.499 ± 0.207 Vinylpyrrolidone 0.370 ± 0.206 N-vinylacetamide    0 ± 0.231

The additional nonionic hydrophilic monomers may be chosen especially from those of formula (III), alone or as a mixture:

in which:

-   -   R′₁ is hydrogen or —CH₃;     -   Z″ is a divalent group chosen from —COO—, —CONH—, —CONCH₃—,         —OCO—, —SO₂, —CO—O—CO—, —CO—CH₂—CO— and —O—; preferably COO and         CONH;     -   x″ is 0 or 1;     -   R″ is a saturated or unsaturated, optionally aromatic, linear,         branched or cyclic carbon-based radical of 1 to 30 carbon atoms,         possibly comprising 1 to 18 heteroatoms chosen from O, N, S, F,         Si and P.

In the radical R″, the heteroatom(s), when they are present, may be intercalated in the chain of said radical, or alternatively said radical may be substituted with one or more groups comprising them, such as hydroxyl, ester, amide, urethane or urea.

R″ may especially be a methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, phenyl or benzyl radical, or a radical of formula —CH₂—CH₂—CH₂OH, —CH₂—CH₂—OH, —CH₂—CH₂—CH₂OH or furfuryl.

The additional hydrophilic nonionic monomers are especially chosen from the following monomers: methyl methacrylate, methyl acrylate, ethyl methacrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, tetrahydrofurfuryl methacrylate, tetrahydrofurfuryl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, ethoxyethyl methacrylate, ethoxyethyl acrylate, N-isopropylacrylamide, N-isopropylmeth-acrylamide, N,N-dimethylacrylamide, N,N-dimethylmeth-acrylamide, vinyl acetate, methyl vinyl ether, ethyl vinyl ether, vinylpyrrolidone, vinylcaprolactam, N-vinylacetamide, hydroxypropyl acrylate, N-vinyllactam, acrylamide, N-methylacrylamide, N,N-dimethylacrylamide, N-methyl-N-vinylacetamide, N-vinylformamide, N-methyl-N-vinylformamide, vinyl alcohol (copolymerized in the form of vinyl acetate and then hydrolyzed).

The additional nonionic hydrophilic monomer, alone or as a mixture, may not be present in the polymer according to the invention (0%), or alternatively may be present in an amount that may range up to 50% by weight, relative to the weight of the final polymer; it may especially be present in an amount of from 0.1% to 35% by weight, preferably from 1% to 25% by weight, for example from 3% to 15% by weight, or even from 5% to 9.5% by weight, relative to the total weight of the polymer.

However, it has been found that when this additional nonionic hydrophilic monomer is chosen from methyl acrylate, methyl methacrylate and isopropyl acrylate, these monomers could not be present in an amount of greater than or equal to 10% by weight. These monomers may thus be present in a proportion of 0-9.5% by weight, especially from 0.1% to 8% by weight and preferably from 1% to 5% by weight in the final polymer.

In one particular embodiment of the invention, the polymer consists essentially of monomer of formula (I), alone or as a mixture, and of monomers of formula (IIa), alone or as a mixture; said copolymer being neutralized as defined later.

When it is ready to be used to prepare compositions according to the invention, for example, the copolymer according to the invention is in a form neutralized (its amine units are neutralized) with at least one particular neutralizer chosen from organic acids in the Brönsted sense.

This means that the monomers, especially those of formula (IIa) and/or the polymer, have been neutralized with at least one such neutralizer.

It is thus possible to neutralize the amine units of the monomers included in the constitution of the polymer, in particular the amine units of the cationic monomers of formula (IIa), before their polymerization, and then to copolymerize the neutralized monomers in order to obtain the polymer according to the invention; this will then be referred to as preneutralization.

It is also possible first to polymerize the non-neutralized monomers, and then to neutralize the polymer after its formation.

Preferably, the polymer is neutralized after its formation.

The neutralizers of organic acid type may be chosen from linear, branched or cyclic aliphatic acids and/or unsaturated or aromatic acids, and may especially contain 1 to 1000 carbon atoms and especially 2 to 500 carbon atoms. They contain at least one acid function in the Brönsted sense, and especially one or more carboxylic, sulfonic and/or phosphonic acid groups. They may also comprise one or more heteroatoms chosen from O, N, Si, F and P, for example in the form of hydroxyl groups.

Neutralizers that may be used in particular include linear, branched or cyclic, saturated or unsaturated, optionally aromatic fatty acids containing 6 to 32 and especially 8 to 28 carbon atoms, and comprising at least one COOH or sulfonic acid (—SO₃H) function.

Linear, branched or cyclic, saturated or unsaturated, optionally aromatic hydroxy acids, especially α-hydroxy acids, containing 6 to 32 and especially 8 to 28 carbon atoms, and comprising at least one COOH or sulfonic acid (—SO₃H) function may also be used.

Alkylbenzenesulfonic acids in which the alkyl group may contain from 4 to 30 and especially from 6 to 24 carbon atoms may also be used.

Amphoteric neutralizers, especially of the alkylbetaine or alkylamidopropylbetaine type, in which the alkyl group may contain 1 to 30, especially 4 to 24 or even 6 to 22 carbon atoms, may also be used; mention may be made in particular of cocoamidopropylbetaine.

Mention may be made especially of α-hydroxyethanoic acid, α-hydroxyoctanoic acid, α-hydroxycaprylic acid, ascorbic acid, acetic acid, benzoic acid, behenic acid, capric acid, citric acid, caproic acid, caprylic acid, dodecylbenzenesulfonic acid, 2-ethylcaproic acid, folic acid, fumaric acid, galactaric acid, gluconic acid, glycolic acid, 2-hexadecyleicosanoic acid, hydroxycaproic acid, 12-hydroxystearic acid, isolauric acid (or 2-butyloctanoic acid), isomyristic acid (or 2-hexyloctanoic acid), isoarachidic acid (or 2-octyldodecanoic acid), isolignoceric acid (or 2-decyltetradecanoic acid), lactic acid, lauric acid, malic acid, myristic acid, oleic acid, palmitic acid, propionic acid, sebacic acid, stearic acid, tartaric acid, terephthalic acid, trimesic acid, undecylenic acid, propylbetaine, cocoamidopropylbetaine, and betaine hydrochloride of formula [(CH₃)₃N+CH₂CO₂H.Cl—], and mixtures thereof.

Caproic acid, 2-ethylcaproic acid, oleic acid, behenic acid, stearic acid, acetic acid, citric acid, tartaric acid, betaine hydrochloride and/or gluconic acid is preferably used as neutralizer, and preferentially betaine hydrochloride and/or behenic acid.

Advantageously, the neutralizer may have a log P value of less than or equal to 2, for example between −8 and 2, preferably between −6 and 1 and especially between −6 and 0.

However, it may have a log P of greater than 2, preferably greater than or equal to 2.5, especially greater than 3 and in particular between 3 and 15, or even between 3.5 and 10.

The log P values are known and are determined according to a standard test that determines the concentration of the monomer in 1-octanol and water, as described above.

The log P value of certain common acids is given below for information purposes:

Acetic acid −0.285 +/− 0.184  Propionic acid 0.246 +/− 0.184 Citric acid −1.721 +/− 0.396  Gluconic acid −3.175 +/− 0.852  Benzoic acid 1.895 +/− 0.206 Stearic acid 8.216 +/− 0.186 Behenic acid 10.342 +/− 0.186  Oleic acid 7.698 +/− 0.199

The term “neutralization” means the action of an organic acid according to the invention, and comprising at least one acid function in the Brönsted sense, on all or part of the monomers and/or polymer mentioned above, comprising at least one basic function in the Brönsted sense.

The neutralizer, alone or as a mixture, may be added in an amount of from 0.01 to 3 and especially 0.05 to 2.5 molar equivalents, or even 0.1 to 2 molar equivalents, relative to the total amine functions of the polymer or of the monomers.

It is thus possible to underneutralize the polymer, i.e. the neutralizer may be present in an amount necessary to neutralize 1% to 99%, especially 5% to 90% or even 10% to 80% of the total amine functions of the polymer or of the monomers; this means that it is present in an amount of from 0.01 to 0.99 and especially 0.05 to 0.9 molar equivalent, or even 0.1 to 0.8 molar equivalent.

It is also possible to overneutralize the polymer, i.e. the neutralizer may be present in an amount necessary to neutralize 101% to 300%, especially from 120% to 250% or even from 150% to 200% of the total amine functions of the polymer or of the monomers; this may be the case when it is desired to ensure that the polymer has a suitable pH range and/or ionic strength with respect to the envisioned formulations. It may thus be present in an amount of from 1.01 to 3 and especially 1.2 to 2.5 molar equivalents, or even 1.5 to 2 molar equivalents, relative to the total amine functions of the polymer or of the monomers.

Preferably, the neutralizer, alone or as a mixture, is present in a stoichiometric amount relative to the total amine functions of the polymer or of the monomers; it is thus present in an amount necessary to neutralize 100% of the amine units of the polymer or of the monomers, i.e. 1 molar equivalent.

Preferentially, the nature and amount of neutralizer may be determined by a person skilled in the art so as finally to obtain a water-soluble or water-dispersible polymer.

The polymers that are most particularly preferred are those in which:

-   -   the monomer of formula (I), alone or as a mixture, is present in         a proportion of from 10% to 80% by weight, especially from 20%         to 60% by weight and preferably from 30% to 50% by weight,         relative to the weight of the final polymer, and is chosen,         alone or as a mixture, from poly(ethylene glycol)         (meth)acrylates, preferably those with a molecular weight of         between 350 and 13000 g/mol and especially between 500 and 8000         g/mol; and     -   the “essentially cationic” monomer is present in a proportion of         from 20% to 90% by weight, especially from 40% to 80% by weight         and preferably from 50% to 70% by weight relative to the weight         of the final polymer, and is chosen, alone or as a mixture, from         dimethylaminopropyl (meth)acrylamide, dimethyl-aminoethyl         (meth)acrylamide, diethylaminoethyl (meth)acrylate,         dimethylaminoethyl (meth)acrylate, vinylimidazole, vinylpyridine         and morpholinoethyl (meth)acrylate; and     -   the polymer is neutralized with a neutralizer chosen from         2-ethylcaproic acid, oleic acid, behenic acid, stearic acid,         acetic acid, citric acid, tartaric acid, betaine hydrochloride         and/or gluconic acid, and preferentially behenic acid and/or         betaine hydro-chloride.

The polymers that are even more particularly preferred are those in which:

-   -   the monomer of formula (I), alone or as a mixture, is present in         a proportion of from 10% to 80% by weight, especially from 20%         to 60% by weight and preferably from 30% to 50% by weight,         relative to the weight of the final polymer, and is chosen,         alone or as a mixture, from poly(ethylene glycol)         (meth)acrylates, preferably those with a molecular weight of         between 350 and 13000 g/mol and especially between 500 and 8000         g/mol; and     -   the “essentially cationic” monomer is present in a proportion of         from 20% to 90% by weight, especially from 40% to 80% by weight         and preferably from 50% to 70% by weight, relative to the weight         of the final polymer, and is chosen, alone or as a mixture, from         dimethylaminopropyl (meth)acrylamide, and     -   the polymer is neutralized with a neutralizer chosen from         behenic acid and/or betaine hydrochloride.

The polymers according to the invention may be prepared according to the usual standard radical polymerization methods known to those skilled in the art, and as described, for example, in the book “Chimie et physicochimie des polymeres” by Gnanou et al. (published by Dunod).

These polymers may especially be prepared by:

-   -   direct solution polymerization in water with optional         preneutralization of the cationic unit;     -   emulsion polymerization in water with optional preneutralization         of the cationic unit with use of a surfactant;     -   polymerization in an organic solvent, such as ethanol or methyl         ethyl ketone, with optional preneutralization of the cationic         unit, followed by a step of dissolution or dispersion in water         with evaporation of the solvent.

These polymerizations may be performed in the presence of a radical initiator especially of peroxide type (Trigonox 21S: tert-butyl peroxy-2-ethylhexanoate) or azo type (AIBN V50: 2,2′-azobis(2-amidinopropane) dihydrochloride) or potassium ammonium persulfate, which may be present in a proportion of from 0.3% to 5% by weight relative to the total weight of the monomers.

The polymers according to the invention are noncrosslinked. They are in the form of statistical, preferably film-forming, ethylenic copolymers of one more ethylenic monomers containing PEG groups (the PEG groups are pendent along the backbone) and of one or more ethylenic monomers comprising neutralize it cationic functions (nonquaternary neutralized amines) and, optionally, one or more other nonionic and/or amphoteric and/or anionic hydrophilic ethylenic comonomers, which are preferably monovalent.

The term “ethylenic” polymer means a polymer obtained by polymerization of ethylenically unsaturated monomers.

The term “film-forming” polymer means a polymer that can form, by itself or in the presence of an auxiliary film-forming agent, a continuous film that adheres to a support, especially to keratin materials.

They have a weight-average molecular mass (Mw) that is preferably between 500 and 5000000, especially between 1000 and 3000000 and more preferentially between 2000 and 2000000, or even between 4000 and 500000, inter alia between 7000 and 400000, even better between 20000 and 350000 and better still between 150000 and 300000. The weight-average molar masses (Mw) are determined by gel permeation chromatography or by light scattering, depending on the accessibility of the method (solubility of the polymers under consideration).

The polymers according to the invention may preferably be conveyed in aqueous medium, i.e. they are preferably water-soluble or water-dispersible.

The dissolution or dispersion in water may be performed by direct dissolution of the polymer if it is soluble, or alternatively by neutralization of the amine units so as to make the polymer soluble or dispersible in water.

The dissolution or dispersion in water may also be performed via an intermediate step of dissolution in an organic solvent followed by the addition of water before evaporation of the organic solvent.

Moreover, it has been found that the polymers according to the invention advantageously have a viscosity in water that is adequate for the envisioned applications, which may be, for example, between 1 and 1000 mPa·s, preferably between 1.5 and 750 mPa·s and better still between 2 and 500 mPa·s.

The viscosity is measured using a Brookfield viscometer, for a solution containing 15% by weight of polymer in water or methyl ethyl ketone (solvent chosen as a function of the solubility of the polymer and/or of the polymerization method), at 25° C., with a needle-type spindle chosen from the model numbers 00 to 07 from Brookfield, preferably a No. 1 spindle; for a measuring time of 5 minutes, at a speed of between 0.1 and 6 rpm. The viscosity is measured after total dissolution of the polymer in water or methyl ethyl ketone.

In addition, the polymers according to the invention may preferably have a glass transition temperature (Tg) of between −150° C. and 20° C., especially −120° C. and 10° C. and better still between −100° C. and 0° C.; the Tg is measured according to the method given before the examples.

The polymers according to the invention may preferably have a melting point (m.p.) of between −100° C. and 80° C., especially between −80° C. and 50° C. and better still between −70° C. and 45° C., or even between −10° C. and 25° C.

In addition, the polymers according to the invention preferably have a water uptake of between 3% and 150% by weight, preferably between 4% and 100% by weight and especially between 5% and 50% by weight, at 75% relative humidity (75% RH); the water uptake is measured according to the method given before the examples.

They may also have a water uptake of between 3% and 200% by weight, preferably between 55% and 150% by weight and especially between 60% and 120% by weight, or even between 70% and 100% by weight, at 85% relative humidity (85% RH).

The polymers according to the invention find a most particular application in the field of cosmetics. They may be present in the composition in dissolved form, for example in water or an organic solvent, or alternatively in the form of an aqueous or organic dispersion.

They may be used in the cosmetic or pharmaceutical compositions according to the invention in a proportion of from 0.01% to 50% by weight of solids, especially from 0.1% to 30% by weight or even from 0.3% to 10% by weight and better still from 1% to 3% by weight relative to the total weight of the composition.

The cosmetic or pharmaceutical compositions according to the invention comprise, besides said polymers, a physiologically acceptable medium, especially a cosmetically, dermatologically or pharmaceutically acceptable medium, i.e. a medium that is compatible with keratin materials such as facial or bodily skin, the hair, the eyelashes, the eyebrows and the nails.

The composition may thus comprise a hydrophilic medium comprising water or a mixture of water and hydrophilic organic solvent(s), for instance alcohols and especially linear or branched C1-C6 monoalcohols, for instance ethanol, isopropanol or n-propanol, and polyols, for instance glycerol, digylcerol, propylene glycol, sorbitol or pentylene glycol, and polyethylene glycols, or alternatively hydrophilic C2 ethers and C₂-C₄ aldehydes.

The water or the mixture of water and hydrophilic organic solvents may be present in the composition according to the invention in a content ranging from 0.1% to 99% by weight and preferably from 10% to 80% by weight relative to the total weight of the composition.

The composition may also comprise a fatty phase, which may comprise fatty substances that are liquid at room temperature (in general 25° C.) and/or fatty substances that are solid at room temperature, such as waxes, pasty fatty substances and gums, and mixtures thereof. These fatty substances may be of animal, plant, mineral or synthetic origin. This fatty phase may also contain lipophilic organic solvents.

As fatty substances that are liquid at room temperature, often referred to as oils, which may be used in the invention, mention may be made of: hydrocarbon-based oils of animal origin such as perhydrosqualene; hydrocarbon-based plant oils such as liquid triglycerides of fatty acids of 4 to 10 carbon atoms, for instance heptanoic or octanoic acid triglycerides, or alternatively sunflower oil, maize oil, soybean oil, grapeseed oil, sesame seed oil, apricot oil, macadamia oil, castor oil, avocado oil, caprylic/capric acid triglycerides, jojoba oil, shea butter, linear or branched hydrocarbons of mineral or synthetic origin, such as liquid paraffin and derivatives thereof, petroleum jelly, polydecenes, hydrogenated polyisobutene such as parleam; synthetic esters and ethers, especially of fatty acids, for instance purcellin oil, isopropyl myristate, 2-ethyl-hexyl palmitate, 2-octyldodecyl stearate, 2-octyl-dodecyl erucate, isostearyl isostearate; hydroxylated esters, for instance isostearyl lactate, octyl hydroxy-stearate, octyldodecyl hydroxystearate, diisostearyl malate, triisocetyl citrate, and fatty alcohol heptanoates, octanoates and decanoates; polyol esters, for instance propylene glycol dioctanoate, neopentyl glycol diheptanoate and diethylene glycol diisononanoate; and pentaerythritol esters; fatty alcohols containing from 12 to 26 carbon atoms, for instance octyldodecanol, 2-butyloctanol, 2-hexyl-decanol, 2-undecylpentadecanol and oleyl alcohol; partially hydrocarbon-based fluoro oils and/or partially silicone-based fluoro oils; silicone oils, for instance volatile or non-volatile, linear or cyclic polymethylsiloxanes (PDMSs), which are liquid or pasty at room temperature, for instance cyclomethicones, dimethicones, optionally comprising a phenyl group, for instance phenyl trimethicones, phenyltrimethylsiloxy-diphenylsiloxanes, diphenylmethyldimethyltrisiloxanes, diphenyl dimethicones, phenyl dimethicones and polymethylphenylsiloxanes; mixtures thereof.

These oils may be present in a content ranging from 0.01% to 90% and better still from 0.1% to 85% by weight relative to the total weight of the composition.

The composition according to the invention may also comprise one or more physiologically acceptable organic solvents.

These solvents may be generally present in a content ranging from 0.1% to 90%, preferably from 0.5% to 85%, more preferably from 10% to 80% and better still from 30% to 50% by weight, relative to the total weight of the composition.

Mention may be made especially, besides the hydrophilic organic solvents mentioned above, of ketones that are liquid at room temperature such as methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, isophorone, cyclohexanone and acetone; propylene glycol ethers that are liquid at room temperature, such as propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, and dipropylene glycol mono-n-butyl ether; short-chain esters (containing from 3 to 8 carbon atoms in total), such as ethyl acetate, methyl acetate, propyl acetate, n-butyl acetate and isopentyl acetate; ethers that are liquid at 25° C., such as diethyl ether, dimethyl ether or dichlorodiethyl ether; alkanes that are liquid at 25° C., such as decane, heptane, dodecane, isododecane and cyclohexane; aromatic cyclic compounds that are liquid at 25° C., such as toluene and xylene; aldehydes that are liquid at 25° C., such as benzaldehyde and acetaldehyde, and mixtures thereof.

For the purposes of the present invention, the term “wax” means a lipophilic compound that is solid at room temperature (25° C.), which undergoes a reversible solid/liquid change of state, and which has a melting point of greater than or equal to 25° C., which may be up to 120° C. By bringing the wax to the liquid state (melting), it is possible to make it miscible with the oils possibly present and to form a microscopically homogeneous mixture, but, on returning the temperature of the mixture to room temperature, recrystallization of the wax is obtained in the oils of the mixture. The melting point of the wax may be measured using a differential scanning calorimeter (DSC), for example the calorimeter sold under the name DSC 30 by the company Mettler.

The waxes may be hydrocarbon-based waxes, fluoro waxes and/or silicone waxes and may be of plant, mineral, animal and/or synthetic origin. In particular, the waxes have a melting point of greater than 30° C. and better still greater than 45° C. As waxes that may be used in the composition of the invention, mention may be made of beeswax, carnauba wax or candelilla wax, paraffin, microcrystalline waxes, ceresin or ozokerite, synthetic waxes, for instance polyethylene waxes or Fischer-Tropsch waxes, and silicone waxes, for instance alkyl or alkoxy dimethicones containing from 16 to 45 carbon atoms.

The gums are generally polydimethylsiloxanes (PDMSs) of high molecular weight or cellulose gums or polysaccharides, and the pasty substances are generally hydrocarbon-based compounds, for instance lanolins and derivatives thereof, or PDMSs.

The nature and amount of the solid substances depend on the desired mechanical properties and textures. As a guide, the composition may contain from 0.1% to 50% by weight and better still from 1% to 30% by weight of waxes relative to the total weight of the composition.

The composition according to the invention may also comprise, in a particulate phase, pigments and/or nacres and/or fillers usually used in cosmetic compositions.

The composition may also comprise other dyestuffs chosen from water-soluble dyes and/or liposoluble dyes that are well known to those skilled in the art.

The term “pigments” should be understood as meaning white or colored, mineral or organic particles of any shape, which are insoluble in the physiological medium and which are intended to color the composition.

The term “fillers” should be understood as meaning colorless or white, mineral or synthetic, lamellar or non-lamellar particles intended to give body or rigidity to the composition, and/or softness, a matt effect and uniformity to the makeup result.

The term “nacres” should be understood as meaning iridescent particles of any form, produced especially by certain molluscs in their shell, or else synthesized.

The pigments may be present in the composition in a proportion of from 0.01% to 25% and preferably in a proportion of from 3% to 10% by weight of the final composition. They may be white or colored, and mineral or organic. Mention may be made of titanium oxide, zirconium oxide or cerium oxide, and also zinc oxide, iron oxide or chromium oxide, ferric blue, chromium hydrate, carbon black, ultramarines (aluminosilicate polysulfides), manganese pyrophosphate and certain metallic powders such as silver or aluminum powder. Mention may also be made of the D&C pigments and lakes commonly used to give the lips and the skin a makeup effect, which are calcium, barium, aluminum, strontium or zirconium salts.

The nacres may be present in the composition in a proportion of from 0.01% to 20% by weight and preferably in a proportion of about from 3% to 10% by weight. Among the nacres that may be envisioned, mention may be made of natural mother-of-pearl, mica coated with titanium oxide, with iron oxide, with natural pigment or with bismuth oxychloride, and also colored titanium mica.

Among the liposoluble or water-soluble dyes that may be present in the composition, alone or as a mixture, in a proportion of from 0.001% to 15% by weight, preferably 0.01% to 5% by weight and especially from 0.1% to 2% by weight, relative to the total weight of the composition, mention may be made of the disodium salt of ponceau, the disodium salt of alizarin green, quinoline yellow, the trisodium salt of amaranth, the disodium salt of tartrazine, the monosodium salt of rhodamine, the disodium salt of fuchsin, xanthophyll, methylene blue, cochineal carmine, halo-acid dyes, azo dyes, anthraquinone dyes, copper sulfate, iron sulfate, Sudan brown, Sudan red and annatto, and also beetroot juice and carotene.

The composition according to the invention may also comprise one or more fillers, especially in a content ranging from 0.01% to 50% by weight and preferably ranging from 0.02% to 30% by weight, relative to the total weight of the composition. The fillers may be mineral or organic in any form, platelet-shaped, spherical or oblong. Mention may be made of talc, mica, silica, kaolin, polyamide (Nylon®) powder, poly-β-alanine powder and polyethylene powder, powders of tetrafluoroethylene polymers (Teflon®), lauroyllysine, starch, boron nitride, hollow polymer microspheres such as those of polyvinylidene chloride/acrylonitrile, for instance Expancel® (Nobel Industrie), of acrylic acid-copolymers (Polytrap® from the company Dow Corning) and silicone resin microbeads (for example Tospearls® from Toshiba), elastomeric polyorganosiloxane particles, precipitated calcium carbonate, magnesium carbonate, magnesium hydrocarbonate, hydroxyapatite, hollow silica microspheres (Silica Beads® from Maprecos), glass or ceramic microcapsules, and metal soaps derived from organic carboxylic acids containing from 8 to 22 carbon atoms and preferably from 12 to 18 carbon atoms, for example zinc, magnesium or lithium stearate, zinc laurate or magnesium myristate.

The composition may also comprise an additional polymer such as a film-forming polymer. According to the present invention, the term “film-forming polymer” means a polymer capable, by itself or in the presence of an auxiliary film-forming agent, of forming a continuous film that adheres to a support and especially to keratin materials. Among the film-forming polymers that may be used in the composition of the present invention, mention may be made of synthetic polymers, of free-radical type or of polycondensate type, polymers of natural origin and mixtures thereof, in particular acrylic polymers, polyurethanes, polyesters, polyamides, polyureas and cellulose-based polymers, for instance nitrocellulose.

The composition may also advantageously comprise at least one surfactant that is generally present in an amount of between approximately 0.01% and 50% by weight, preferably between 0.1% and 40%, and even more preferably between 0.5% and 30% relative to the total weight of the composition.

This surfactant may be chosen from anionic, amphoteric, nonionic and cationic surfactants, or mixtures thereof.

The surfactants that are suitable for carrying out the present invention are especially, alone or as a mixture:

-   -   anionic surfactants, among which mention may be made, alone or         as mixtures, of salts (in particular alkaline salts, especially         sodium salts, ammonium salts, amine salts, amino alcohol salts         or magnesium salts) of the following compounds: alkyl sulfates,         alkyl ether sulfates, alkylamido ether sulfates,         alkylarylpolyether sulfates, monoglyceride sulfates; alkyl         sulfonates, alkyl phosphates, alkylamide sulfonates, alkylaryl         sulfonates, α-olefin sulfonates, paraffin sulfonates; alkyl         sulfosuccinates, alkyl ether sulfosuccinates, alkylamide         sulfosuccinates; alkyl sulfosuccinamates; alkyl sulfoacetates;         alkyl ether phosphates; acyl sarcosinates; acyl isethionates and         N-acyltaurates, the alkyl or acyl radical of all of these         various compounds preferably containing from 8 to 24 carbon         atoms, and the aryl radical preferably denoting a phenyl or         benzyl group.

Mention may also be made of fatty acid salts such as the salts of oleic, ricinoleic, palmitic and stearic acids, coconut oil acid or hydrogenated coconut oil acid; acyl lactylates in which the acyl radical contains 8 to 20 carbon atoms; alkyl-D-galactosiduronic acids and their salts, as well as polyoxyalkylenated (C₆-C₂₄) alkyl ether carboxylic acids, polyoxyalkylenated (C₆-C₂₄) alkylaryl ether carboxylic acids, polyoxyalkylenated (C₆-C₂₄) alkylamido ether carboxylic acids and their salts, in particular those containing from 2 to 50 ethylene oxide groups, and mixtures thereof.

-   -   nonionic surfactants, among which mention may be made, alone or         as mixtures, of polyethoxylated, polypropoxylated or         polyglycerolated fatty acids, alkylphenols, α-diols or alcohols         having a fatty chain containing, for example, 8 to 18 carbon         atoms, it being possible for the number of ethylene oxide or         propylene oxide groups to range in particular from 2 to 50 and         for the number of glycerol groups to range in particular from 2         to 30.

Mention may also be made of copolymers of ethylene oxide and of propylene oxide, condensates of ethylene oxide and of propylene oxide with fatty alcohols; polyethoxylated fatty amides preferably having from 2 to 30 mol of ethylene oxide, polyglycerolated fatty amides containing on average 1 to 5, and in particular 1.5 to 4, glycerol groups; oxyethylenated fatty acid esters of sorbitan having from 2 to 30 mol of ethylene oxide; fatty acid esters of sucrose, fatty acid esters of polyethylene glycol, alkylpolyglycosides, N-alkylglucamine derivatives, amine oxides such as (C₁₀-C₁₄)alkylamine oxides or N-acylaminopropylmorpholine oxides;

-   -   amphoteric surfactants, among which mention may be made, alone         or as mixtures, of aliphatic secondary or tertiary amine         derivatives in which the aliphatic radical is a linear or         branched chain containing 8 to 22 carbon atoms and containing at         least one water-soluble anionic group (for example carboxylate,         sulfonate, sulfate, phosphate or phosphonate); mention may also         be made of (C₈-C₂₀)alkylbetaines, sulfobetaines,         (C₈-C₂₀)alkylamido(C₁-C₆)alkylbetaines or         (C₈-C₂₀)alkylamido(C₁-C₆)alkylsulfobetaines;     -   cationic surfactants, among which mention may be made, alone or         as mixtures, of:         A) the quaternary ammonium salts of general formula (XVI) below:

in which X⁻ is an anion chosen from the group of halides (chloride, bromide or iodide) or (C₂-C₆)alkyl sulfates, more particularly methyl sulfate, phosphates, alkyl or alkylaryl sulfonates, anions derived from organic acid, such as acetate or lactate, and a) the radicals R₁ to R₃, which may be identical or different, represent a linear or branched aliphatic radical containing from 1 to 4 carbon atoms, or an aromatic radical such as aryl or alkylaryl. The aliphatic radicals can comprise heteroatoms such as, in particular, oxygen, nitrogen, sulfur or halogens. The aliphatic radicals are chosen, for example, from alkyl, alkoxy and alkylamide radicals, R₄ denotes a linear or branched alkyl radical containing from 16 to 30 carbon atoms.

The cationic surfactant is preferably a behenyltrimethylammonium salt (for example chloride).

b) the radicals R₁ and R₂, which may be identical or different, represent a linear or branched aliphatic radical containing from 1 to 4 carbon atoms, or an aromatic radical such as aryl or alkylaryl. The aliphatic radicals can comprise heteroatoms such as, in particular, oxygen, nitrogen, sulfur or halogens. The aliphatic radicals are chosen, for example, from alkyl, alkoxy, alkylamide and hydroxyalkyl radicals containing from about 1 to 4 carbon atoms; R₃ and R₄, which may be identical or different, denote a linear or branched alkyl radical containing from 12 to 30 carbon atoms, said radical comprising at least one ester or amide function. R₃ and R₄ are chosen in particular from (C₁₂-C₂₂)alkylamido(C₂-C₆)alkyl and (C₁₂-C₂₂)alkylacetate radicals;

The cationic surfactant is preferably a stearamidopropyldimethyl (myristyl acetate) ammonium salt (for example chloride).

B)—the quaternary ammonium salts of imidazolinium, such as, for example, that of formula (XVII) below:

in which R₅ represents an alkenyl or alkyl radical containing from 8 to 30 carbon atoms, for example fatty acid derivatives of tallow, R₆ represents a hydrogen atom, a C₁-C₄ alkyl radical or an alkenyl or alkyl radical containing from 8 to 30 carbon atoms, R₇ represents a C₁-C₄ alkyl radical, R₈ represents a hydrogen atom or a C₁-C₄ alkyl radical, and X is an anion chosen from the group of halides, phosphates, acetates, lactates, alkyl sulfates, alkyl sulfonates or alkylaryl sulfonates. R₅ and R₆ preferably denote a mixture of alkenyl or alkyl radicals containing from 12 to 21 carbon atoms, such as, for example, fatty acid derivatives of tallow, R₇ denotes methyl and R₈ denotes hydrogen. Such a product is, for example, Quaternium-27 (CTFA 1997) or Quaternium-83 (CTFA 1997), which are sold under the names “Rewoquat” W75, W90, W75PG and W75HPG by the company Witco, C)—the diquaternary ammonium salts of formula (XVIII):

in which R₉ denotes an aliphatic radical containing from about 16 to 30 carbon atoms, R₁₀, R₁₁, R₁₂, R₁₃ and R₁₄, which may be identical or different, are chosen from hydrogen and an alkyl radical containing from 1 to 4 carbon atoms, and X is an anion chosen from the group of halides, acetates, phosphates, nitrates and methyl sulfates. Such diquaternary ammonium salts in particular comprise propanetallowediammonium dichloride; D)—the quaternary ammonium salts containing at least one ester function, of formula (XIX) below:

in which:

-   -   R₁₅ is chosen from C₁-C₆ alkyl radicals and C₁-C₆ hydroxyalkyl         or dihydroxyalkyl radicals;     -   R₁₆ is chosen from:         -   a radical

-   -   -   linear or branched, saturated or unsaturated C₁-C₂₂             hydrocarbon-based radicals R₂₀,         -   a hydrogen atom,

    -   R₁₈ is chosen from:         -   a radical

-   -   -   linear or branched, saturated or unsaturated C₁-C₆             hydrocarbon-based radicals R₂₂,         -   a hydrogen atom,

    -   R₁₇, R₁₉ and R₂₁, which may be identical or different, are         chosen from linear or branched, saturated or unsaturated C₇-C₂₂         hydrocarbon-based radicals;

    -   n, p and r, which may be identical or different, are integers         ranging from 2 to 6;

    -   y is an integer ranging from 1 to 10;

    -   x and z, which may be identical or different, are integers         ranging from 0 to 10;

    -   X⁻ is a simple or complex, organic or inorganic anion; with the         proviso that the sum x+y+z is from 1 to 15, that when x is 0,         then R₁₆ denotes R₂₀ and that when z is 0, then R₁₈ denotes R₂₂.

The composition according to the invention may also comprise ingredients commonly used in cosmetics, such as vitamins, fragrances, nacres, thickeners, gelling agents, trace elements, softeners, sequestrants, fragrances, acidifying or basifying agents, preserving agents, sunscreens, surfactants, antioxidants, hair-loss counteractants, antidandruff agents, propellants and ceramides, or mixtures thereof. Needless to say, a person skilled in the art will take care to select this or these optional additional compound(s), and/or the amount thereof, such that the advantageous properties of the composition according to the invention are not, or are not substantially, adversely affected by the envisioned addition.

The composition according to the invention may be in the form of a suspension, a dispersion, especially of oil in water by means of vesicles; an optionally thickened or even gelled oily solution; an oil-in-water, water-in-oil or multiple emulsion; a gel or a mousse; an oily or emulsified gel; a dispersion of vesicles, especially lipid vesicles; a two-phase or multi-phase lotion; a spray. This composition may have the appearance of a lotion, a cream, a pomade, a soft paste, an ointment, a solid cast or molded especially in stick or dish form, or alternatively a compacted solid.

A person skilled in the art may select the appropriate galenical form, and also the method for preparing it, on the basis of his general knowledge, taking into account, firstly, the nature of the constituents used, especially their solubility in the support, and, secondly, the intended use of the composition.

The cosmetic composition according to the invention may be in the form of a care and/or makeup product for bodily or facial skin, the lips and the hair, an antisun or self-tanning product, or even a haircare product.

It especially finds a particularly advantageous use in the field of haircare, especially for holding the hairstyle or shaping the hair. The hair compositions are preferably shampoos, hairsetting gels or lotions, blow-drying lotions, and fixing and styling compositions such as lacquers or sprays. The lotions may be packaged in various forms, especially in vaporizers or pump-dispenser bottles or in aerosol containers in order to apply the composition in vaporized form or in the form of a mousse.

In one preferred embodiment, the compositions in accordance with the invention may be used for washing or treating keratin materials such as the hair, the skin, the eyelashes, the eyebrows, the nails, the lips and the scalp, and more particularly the hair.

The compositions according to the invention may be detergent compositions such as shampoos, shower gels and bubble baths. In this embodiment of the invention, the compositions comprise at least one washing base, which is generally aqueous, which may comprise from 5% to 35% by weight of surfactant.

A subject of the invention is thus also a process for treating keratin materials such as the skin or the hair, characterized in that it consists in applying to the keratin materials a cosmetic composition as defined above, and then optionally in rinsing with water.

Thus, this process according to the invention allows hold of the hairstyle, and treatment, washing or care of or makeup-removal from the skin, the hair or any other keratin material.

In another preferred embodiment, the compositions of the invention may be in the form of a rinse-out or leave-in hair conditioner, compositions for permanent-waving, relaxing, dyeing or bleaching the hair, or alternatively in the form of rinse-out compositions, to be applied before or after dyeing, bleaching, permanent-waving or relaxing the hair, or alternatively between the two steps of a permanent-waving or hair-relaxing operation.

When the composition is in the form of a hair conditioner optionally to be rinsed out, it advantageously contains at least one cationic surfactant, for example in a concentration generally of between 0.1% and 10% by weight and preferably from 0.5% to 5% by weight relative to the total weight of the composition.

The compositions of the invention may also be in the form of washing compositions for the skin, in particular in the form of bath or shower solutions or gels or makeup-removing products.

The compositions according to the invention may also be in the form of aqueous or aqueous-alcoholic lotions for skincare and/or haircare.

A subject of the invention is also a cosmetic process for making up or caring for keratin materials, especially bodily or facial skin, the nails, the hair and/or the eyelashes, comprising the application to said materials of a cosmetic composition as defined above.

The invention is illustrated in greater detail in the examples that follow.

Measurement of the Tg

A film is made using an aqueous solution containing 6% by weight of polymer and dried for 48 hours under a controlled atmosphere at 50% relative humidity and 25° C. The films thus obtained have a thickness of between 10 and 20 μm.

The measuring apparatus is a DSC (TA Instruments).

The sample obtained from the film is placed in a hermetic crucible and is heated according to the following protocol:

-   -   equilibrium at initial temperature Ti;     -   heating 1: raising of the temperature, at a rate of +10° C./min         to a final temperature: Tf (° C.);     -   isotherm for 1 minute;     -   reducing of the temperature at a rate of −10° C./min to Ti (°         C.);     -   heating 2: raising of the temperature at a rate of +10° C./min         to Tf (° C.);     -   isotherm for 1 minute,         with Ti: initial temperature −120° C.         with Tf: final temperature +120° C.

The Tg values are measured during the heating steps 1 and 2.

Measurement of the Water Uptake

About 1 g of dry polymer is placed in an aluminum crucible 4.5 cm in diameter (0.01 m²). It is left to dry for 48 hours in an oven at 60° C. under reduced pressure. The crucibles are removed and weighed immediately (less than one minute after removing from the oven). W1 is obtained.

The crucibles are then placed in a glove box with a given relative humidity (75% RH or 85% RH) and are left therein for 6 hours. They are then weighed again immediately after removing them from the glove box. W2 is obtained.

The water uptake is calculated in the following manner:

[(W2−W1)×100]/W1

EXAMPLE 1 Step 1

75 ml of methyl ethyl ketone (MEK) are placed in a reactor (4-necked flask) on which are mounted two addition funnels, a condenser and a mechanical stirrer, and are brought to 80° C.

In parallel, a solution 1 is prepared comprising the monomers: 50 g of polyethylene glycol methacrylate (MPEG 550), 50 g of dimethylaminopropylmethacrylamide (DMAPMA) and the initiator: 0.5 g of (Trigonox 21S).

A solution 2 is also prepared, comprising 75 ml of methyl ethyl ketone and 0.5 g of initiator (Trigonox 21S).

Solution 1 is poured dropwise over 1 hour and solution 2 over two hours, into the 4-necked flask reactor. The resulting mixture is then maintained at 80° C. for 5 hours. The orange-yellow solution obtained is cooled. 95 g of polymer are obtained.

The polymer has a Brookfield viscosity at 15% in MEK, at 25° C., measured with a No. 1 needle-type spindle, at a speed of 0.1 rpm, of 7.5 mPa·s.

Step 2

The polymer may then be neutralized in the following manner: 45 g of betaine hydrochloride dissolved in water are added to 95 g of polymer; the solvent (MEK) is then evaporated off on a rotavapor under reduced pressure (80 mbar and 56° C.).

The neutralized polymer according to the invention is soluble in water (at least up to 50% by weight).

Its Tg is −66° C. It has a water uptake at 85% RH of 80%.

Comparative Step 2

For comparative purposes, the polymer obtained in step 1 is neutralized in the following manner: 290 ml of 1N HCl are added with stirring to 95 g of polymer and 200 ml of distilled water; the solvent (MEK) is then evaporated off.

The comparative neutralized polymer is soluble in water (at least up to 50% by weight).

Its Tg is −60° C. It has a water uptake at 85% RH of 51%.

EXAMPLE 2

100 ml of water are placed in a reactor (4-necked flask) on which are mounted two addition funnels, a condenser and a mechanical stirrer, and are brought to 80° C.

In parallel, a solution 1 comprising 50 g of monomer MPEG 550, 1 g of initiator (potassium persulfate KPS) and 50 ml of water is prepared.

A solution 2 comprising 50 g of monomer DMAPMA 100% neutralized with betaine hydrochloride, and 50 g of water, is also prepared.

Solutions 1 and 2 are poured into the 4-necked flask over 1 hour. After 1 hour at 80° C., a mixture of 1 g of KPS in 50 ml of water is added dropwise thereto over 15 minutes.

The resulting mixture is then maintained at 80° C. for 3 hours. 90 g of polymer neutralized with betaine hydrochloride are obtained.

The polymer has a Brookfield viscosity at 15% in water, at 25° C., measured with a No. 1 needle-type spindle, at a speed of 6 rpm, of 164 mPa·s.

The polymer is soluble in water (at least up to 50% by weight).

Its Tg is −60° C. The neutralized polymer has a water uptake at 85% HR of 90%.

PREPARATION EXAMPLES 3 to 25

The following polymers are prepared according to the process of Example 1 (solvent process) or of Example 2 (process in water):

The neutralization may be performed on the cationic monomer before polymerization (preneutralization) or on the polymer (post-neutralization):

Process and Polymer Example Monomers (weight %) neutralization solubility Example 3 MPEG 550 50% Process 1 Water- DMAPMA 50% Post-neutralization soluble betaine hydrochloride Example 4 MPEG 5000 50% Process 2 Water- DMAPMA 50% Preneutralization soluble betaine hydrochloride Example 5 MPEG 5000 75% Process 2 Water- DMAPMA 25% Preneutralization soluble betaine hydrochloride Example 6 MPEG 5000 25% Process 2 Water- DMAPMA 75% Preneutralization soluble betaine hydrochloride Example 7 MPEG 5000 50% Process 1 Water- DMAPMA 50% Post-neutralization soluble betaine hydrochloride Example 8 MPEG 2000 50% Process 1 Water- DMAPMA 50% Post-neutralization soluble betaine hydrochloride Example 9 DMAPMA 50% Process 1 Water- Jeffamine M-1000 Post-neutralization soluble acrylamide 50% betaine hydrochloride Example 10 MPEG 8000 50% Process 1 Water- DMAPMA 50% Post-neutralization soluble betaine hydrochloride Example 11 MPEG 550 40% Process 1 Water- DMAPMA 50% Post-neutralization soluble vinylpyrrolidone 10% betaine hydrochloride Example 12 MPEG 550 40% Process 1 Water- DMAPMA 50% Post-neutralization soluble vinyl acetate 10% betaine hydrochloride Example 13 MPEG 550 40% Process 1 Water- DMAPMA 50% Post-neutralization soluble vinylcaprolactam 10% betaine hydrochloride Example 14 MPEG 550 40% Process 1 Water- DMAPMA 50% Post-neutralization soluble THF MA 10% betaine hydrochloride Example 15 MPEG 550 50% Process 1 Water- DMAPMA 50% Post-neutralization soluble gluconic acid (log p = −3.175) Example 16 MPEG 550 40% Process 1 Water- DMAPMA 50% Post-neutralization soluble vinylpyrrolidone 10% gluconic acid Example 17 MPEG 550 40% Process 1 Water- DMAPMA 50% Post-neutralization soluble vinyl acetate 10% gluconic acid Example 18 MPEG 550 40% Process 1 Water- DMAPMA 50% Post-neutralization soluble vinylcaprolactam 10% gluconic acid Example 19 MPEG 550 50% Process 1 Water- DMAPMA 50% Post-neutralization soluble ethylcaproic acid Example 20 MPEG 550 40% Process 1 Water- DMAPMA 50% Post-neutralization soluble vinylpyrrolidone 10% caproic acid Example 21 MPEG 550 40% Process 1 Water- DMAPMA 50% Post-neutralization soluble vinyl acetate 10% caproic acid Example 22 MPEG 550 40% Process 1 Water- DMAPMA % Post-neutralization soluble vinylcaprolactam 10% caproic acid Example 23 MPEG 550 40% Process 1 Water- DMAPMA 50% Post-neutralization soluble THF MA 10% caproic acid Example 24 MPEG 550 50% Process 1 Water- DMAPMA 50% Post-neutralization dispersible 20% behenic acid Example 25 MPEG 550 50% Process 1 Water- DMAPMA 50% Post-neutralization dispersible oleic acid MPEG: polyethylene glycol methacrylate (with MW = 550, 2000 or 5000) DMAPMA: dimethylaminopropylmethacrylamide Jeffamine M-1000 acrylamide of formula

THF MA: tetrahydrofurfuryl methacrylate

EXAMPLE 26

A composition comprising the following constituents (weight %) is prepared:

-   -   7.5% lauryl ether sulfate     -   2.5% cocobetaine amphoteric surfactant (Dehyton AB30 from         Cognis)     -   5% cocopolyglucoside surfactant (Plantacare 818 UP from Cognis)     -   1.5% polymer of Example 3     -   qs 100% water         The shampoo composition obtained gives a good styling effect.         The cosmetic nature on wet hair is satisfactory. The styling         results obtained after application to heads are good and the         cosmetic properties on dry hair are particularly good. It is         found that this composition provides cosmetic properties         equivalent to those provided by a common conditioning shampoo:         cosmetic nature superior to that of the prior art for equivalent         styling; certain cosmetic criteria (smoothing, softness and         sheen) are better with the composition according to the         invention.

EXAMPLE 27

A composition comprising the following constituents (weight %) is prepared:

-   -   7.5% lauryl ether sulfate     -   2.5% cocobetaine amphoteric surfactant     -   5% cocopolyglucoside surfactant     -   1.5% polymer of Example 24     -   qs 100% water

The resulting composition is applied to heads in a single application, and the following criteria are evaluated (panel of six individuals):

-   -   on wet hair: the smoothing and disentangling     -   on dry hair: the bounce of the rolled-up and dried lock (styling         effect), disentangling and sheen.

The following results are obtained:

-   -   on wet hair, the disentangling and sheen are very good;     -   on dry hair, the styling effect is good; the cosmetic properties         are good, superior to those of the prior art for an equivalent         styling effect; certain cosmetic criteria (smoothing, softness         and sheen) are better with the composition according to the         invention.

The results are collated in the table below (test performed for the composition of Example 27, comprising the polymer of Example 24, and for the composition of Example 26, comprising the polymer of Example 3)

Disen- Disen- tangling Smoothing tangling wet hair wet hair dry hair Sheen Bounce Composition +++ +++ +++ +++ ++ according (softness good good to Example superior to 26 that of the control) Composition ++++ ++++ ++++ according to Example 27 Control ++ ++ ++ ++ 0 (DOP camomile shampoo)

EXAMPLE 28

A composition comprising the following constituents (weight %) is prepared:

-   -   6% polymer of Example 1     -   0.001% preserving agent     -   qs 100% water

The composition is introduced into a pump-dispenser bottle; it is applied to dry and styled hair, and the following criteria are evaluated: the bounce of the rolled-up and dried lock (styling effect). It is found that the bounce of the curls and the styling effect are improved compared with a lock treated with a control composition comprising 6% Resin 28-29-30 polymer from National Starch (VA/crotonates/vinyl neodecanoate copolymer), 0.001% preserving agent and qs 100% water.

EXAMPLE 29

A shampoo comprising the following constituents (weight %) is prepared:

-   -   7.5% lauryl ether sulfate     -   2.5% cocobetaine amphoteric surfactant (Dehyton AB30 from         Cognis)     -   5% cocopolyglucoside surfactant (Plantacare 818 UP from Cognis)     -   qs preserving agent     -   1.5% polymer active material     -   qs 100% water

The resulting composition is applied to heads in a single application, and the following criteria are evaluated (panel of six individuals):

-   -   on wet hair: the smoothing, lightness and ease of disentangling     -   on dry hair: the bounce of the rolled-up and dried lock (styling         effect).

The two polymers below are compared, and the following results are obtained:

Polymer According to the MPEG 550/DMAPMA 50/50 neutralized invention with betaine hydrochloride Comparative MPEG 550/DMAPMA 50/50 neutralized with HCl

The locks treated with the composition according to the invention are softer and silkier; they appear to be more treated. The liveliness (bounce) of the locks is equivalent. 

1. An ethylenic copolymer comprising, as a weight percentage relative to the total weight of the polymer: a) 10-80% by weight of one or more monomers of formula (I):

in which: R1 is a hydrogen atom or a linear or branched hydrocarbon-based radical, of the type C_(p)H_(2p+1), with p being an integer between 1 and 12 inclusive; Z is a divalent group chosen from —COO—, —CONH—, —CONCH₃—, —OCO—, —O—, —SO₂—, —CO—O—CO— and —CO—CH₂—CO—; x is 0 or 1; R2 is a saturated or unsaturated, optionally aromatic, linear, branched or cyclic carbon-based divalent radical of 1 to 30 carbon atoms, possibly comprising 1 to 18 heteroatoms chosen from O, N, S, F, Si and P; m is 0 or 1; n is an integer between 3 and 300 inclusive; R3 is a hydrogen atom or a saturated or unsaturated, optionally aromatic, linear, branched or cyclic carbon-based radical of 1 to 30 carbon atoms, possibly comprising 1 to 20 heteroatoms chosen from O, N, S, F, Si and P; and salts thereof; b) 20-90% by weight of at least one cationic monomer, or a salt thereof, chosen from the monomers of formula (IIa)

in which: R1 is a hydrogen atom or a linear or branched hydrocarbon-based radical of the type C_(p)H_(2p+1), with p being an integer between 1 and 12 inclusive; preferably hydrogen or a methyl, ethyl, propyl or butyl radical; Z′ is a divalent group chosen from —COO—, —CONH—, —CONCH₃—, —OCO— or —O—, —SO₂— —CO—O—CO— or —CO—CH₂—CO—; preferably COO and CONH; x′ is 0 or 1, preferably 1; R′2 is a saturated or unsaturated, optionally aromatic, linear, branched or cyclic divalent carbon-based radical of 1 to 30 carbon atoms, possibly comprising 1 to 18 heteroatoms chosen from O, N, S, F, Si and P; m′ is 0 or 1; X is (a) a guanidino or amidino group, or (b) a group of formula —N(R₆)(R₇) or —P(R₆)(R₇) or —P⁺R₆R₇R₈, with R₆, R₇ and R₈ representing, independently of each other, either (i) a hydrogen atom, or (ii) a linear, branched or cyclic, saturated or unsaturated, optionally aromatic alkyl group containing from 1 to 18 carbon atoms, possibly comprising 1 to 10 heteroatoms chosen from O, N, S, F, Si and P; or (iii) R6 and R7 may form with the nitrogen or phosphorus atom a first saturated or unsaturated, optionally aromatic ring comprising in total 5, 6, 7 or 8 atoms, and especially 4, 5 or 6 carbon atoms and/or 2 to 4 heteroatoms chosen from O, S and N; said first ring possibly being fused with one or more other saturated or unsaturated, optionally aromatic rings each comprising 5, 6 or 7 atoms, and especially 4, 5, 6 or 7 carbon atoms and/or 2 to 4 heteroatoms chosen from O, S and N; or (c) a group —R′6-N—R′7- in which R′6 and R′7 form with the nitrogen atom a saturated or unsaturated, optionally aromatic ring comprising in total 5, 6, 7 or 8 atoms, and especially 4, 5 or 6 carbon atoms and/or 2 to 4 heteroatoms chosen from O, S and N; said ring possibly being fused with one or more other saturated or unsaturated, optionally aromatic rings, each comprising 5, 6 or 7 atoms, and especially 4, 5, 6, 7 or 8 carbon atoms and/or 2 to 4 heteroatoms chosen from O, S and N; said copolymer being at least partially neutralized with at least one neutralizer chosen from organic acids in the Brönsted sense.
 2. The polymer as claimed in claim 1, in which, in formula (I), R1 represents hydrogen or a methyl, ethyl, propyl or butyl radical.
 3. The polymer as claimed in either of the preceding claims, in which, in formula (I), Z represents COO or CONH.
 4. The polymer as claimed in one of the preceding claims, in which, in formula (I), the radical R2 is chosen from: an alkylene radical such as methylene, ethylene, propylene, n-butylene, isobutylene, tert-butylene, n-hexylene, n-octylene, n-dodecylene, n-octadecylene, n-tetradecylene or n-docosanylene; a phenylene radical —C₆H₄— (ortho, meta or para) optionally substituted with a C1-C12 alkyl radical optionally comprising 1 to 25 heteroatoms chosen from O, N, S, F, Si and P; or alternatively a benzylene radical —C₆H₄—CH₂—, optionally substituted with a C1-C12 alkyl radical optionally comprising 1 to 8 heteroatoms chosen from O, N, S, F, Si and P; a pyridinium radical of formula:

with R′1 to R′4, which may be identical or different, chosen from H and a C1-C12 alkyl radical optionally comprising 1 to 8 heteroatoms chosen from O, N, S, F, Si and P; R′1 to R′4 may especially be methyl and/or ethyl; a radical of formula —CH₂—O—CO—O—, CH₂—CH₂—O—CO—O—, —CH₂—CO—O—, —CH₂—CH₂—CO—O—, —CH₂—O—CO—NH—, —CH₂—CH₂—O—CO—NH—; —CH₂—NH—CO—NH—, —CH₂—CH₂—NH—CO—NH—; —CH₂—CHOH—, —CH₂—CH₂—CHOH—, CH₂—CH₂—CH(NH₂)—, —CH₂—CH(NH₂)—, —CH₂—CH₂—CH(NHR′)—, —CH₂—CH(NHR′)—, —CH₂—CH₂—CH(NR′R″)—, —CH₂—CH(NR′R″)—, —CH₂—CH₂—CH₂—NR′—, —CH₂—CH₂—CH₂—O—; —CH₂—CH₂—CHR′—O— with R′ and R″ representing a linear or branched C1-C22 alkyl optionally comprising 1 to 12 heteroatoms chosen from O, N, S, F, Si and P; or a mixture of these radicals.
 5. The polymer as claimed in one of the preceding claims, in which, in formula (I), n is between 5 and 200 inclusive and better still between 7 and 100 inclusive, or even between 9 and 50 inclusive.
 6. The polymer as claimed in one of the preceding claims, in which, in formula (I), R3 is a hydrogen atom; a succinimido, maleimido, mesityl, tosyl, triethoxysilane, phthalimide or —CH₂—CH₂CN radical; or alternatively a benzyl or phenyl radical optionally substituted with a C1-C12 alkyl radical optionally comprising 1 to 8 heteroatoms chosen from O, N, S, F, Si and P; a C1-C30 and especially C1-C22 or even C2-C16 alkyl radical, optionally comprising 1 to 18 heteroatoms chosen from O, N, S, F, Si and P; said benzyl, phenyl or alkyl radicals also possibly comprising a function chosen from the following functions: succinimido; glutarate-succinimido; glutarate; maleimido; mesityl, benzoate; tosyl; triethoxysilane; phthalimide; thioester; benzotriazole carbonate; butyraldehyde; acetaldehyde diethyl acetal; biotin; phospholipid; succinate; N-hydroxysuccinimide; —SO₃H, —COOH, —PO₄, —NR5R6 or —N⁺R5R6R7, with R5, R6 and R7, independently of each other, chosen from H and linear, branched or cyclic C1-C18 alkyls, especially methyl, optionally comprising one or more heteroatoms or alternatively protecting groups such as t-butyloxycarbonyl or 9-fluorenylmethoxycarbonyl.
 7. The polymer as claimed in one of the preceding claims, in which the monomer of formula (I) is chosen, alone or as a mixture, from: poly(ethylene glycol) (meth)acrylate; methylpoly(ethylene glycol) (meth)acrylate; alkylpoly(ethylene glycol) (meth)acrylates; phenylpoly(ethylene glycol) (meth)acrylates; the following monomer:

in which n is preferably between 3 and 100 inclusive and especially 5 to 50 inclusive, or even 7 to 30 inclusive.
 8. The polymer as claimed in one of the preceding claims, in which the monomer of formula (I) has a molecular weight of between 350 and 13000 g/mol and especially between 500 and 8000 g/mol.
 9. The polymer as claimed in one of the preceding claims, in which the monomer of formula (I) is chosen from poly(ethylene glycol) (meth)acrylates and methylpoly(ethylene glycol) (meth)acrylates, preferably those with a molecular weight of between 350 and 13000 g/mol and especially between 500 and 8000 g/mol.
 10. The polymer as claimed in one of the preceding claims, in which the monomer of formula (I) is chosen from poly(ethylene glycol) (meth)acrylates and in particular those with a molecular weight of between 350 and 13000 g/mol and especially between 500 and 8000 g/mol.
 11. The polymer as claimed in one of the preceding claims, in which the monomer of formula (I), alone or as a mixture, is present in a proportion of from 20% to 60% by weight and preferably from 30% to 50% by weight relative to the weight of the final polymer.
 12. The polymer as claimed in one of the preceding claims, in which, in the monomer of formula (IIa), the radical R′2 is chosen from: an alkylene radical such as methylene, ethylene, propylene, n-butylene, isobutylene, tert-butylene, n-hexylene, n-octylene, n-dodecylene, n-octadecylene, n-tetradecylene or n-docosanylene; a phenylene radical —C₆H₄— (ortho, meta or para), optionally substituted with a C1-C12 alkyl radical optionally comprising 1 to 25 heteroatoms chosen from N, O, S, F, Si and/or P; or alternatively a benzylene radical —C₆H₄—CH₂—, optionally substituted with a C1-C12 alkyl radical optionally comprising 1 to 25 heteroatoms chosen from O, N, S, F, Si and P; a radical of formula —CH₂—O—CO—O—, CH₂—CH₂—O—CO—O—, —CH₂—CO—O—, —CH₂—CH₂—CO—O—, —[(CH₂)₅—CO—]_(n)—, —CH₂—CH(CH₃)—O—, —(CH₂)₂—O—, —CH₂—O—CO—NH—, —CH₂—CH₂—O—CO—NH—; —CH₂—NH—CO—NH— or —CH₂—CH₂—NH—CO—NH—, —CH₂—CHOH—, —CH₂—CH₂—CHOH—, —CH₂—CH₂—CH(NH₂)—, —CH₂—CH(NH₂)—, —CH₂—CH₂—CH(NHR′)—, —CH₂—CH(NHR′)—, —CH₂—CH₂—CH(NR′R″)—, —CH₂—CH(NR′R″)—, —CH₂—CH₂—CH₂—NR′—, —CH₂—CH₂—CH₂—O—; —CH₂—CH₂—CHR′—O— with R′ and R″ representing a linear or branched C1-C22 alkyl optionally comprising 1 to 12 heteroatoms chosen from O, N, S, F, Si and P; or a mixture of these radicals.
 13. The polymer as claimed in one of the preceding claims, in which, in the monomer of formula (IIa), the radicals R6 and R7 are chosen from hydrogen and a methyl, ethyl, propyl, isopropyl, n-butyl, t-butyl, isobutyl, octyl, lauryl or stearyl group; preferably hydrogen, methyl or ethyl.
 14. The polymer as claimed in one of the preceding claims, in which, in the monomer of formula (IIa), X is a radical chosen from radicals of pyridine, indolyl, isoindolinyl, imidazolyl, imidazolinyl, piperidyl, pyrazolinyl, pyrazolyl, quinoline, pyrazolinyl, pyridyl, piperazinyl, pyrrolidinyl, quinidinyl, thiazolinyl, morpholine, guanidino or amidino type, and mixtures thereof.
 15. The polymer as claimed in one of the preceding claims, in which the monomer of formula (IIa) is chosen, alone or as a mixture, from: dimethylaminopropyl(meth)acrylamide, dimethylaminoethyl(meth)acrylamide, diethylaminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, vinylimidazole, vinylpyridine and morpholinoethyl (meth)acrylate, and the monomers below:


16. The polymer as claimed in one of the preceding claims, in which the cationic monomer of formula (IIa) is present in a proportion of from 40% to 80% by weight and preferably from 50% to 70% by weight relative to the weight of the final polymer.
 17. The polymer as claimed in one of the preceding claims, comprising one or more additional ionic monomers chosen from the amphoteric monomers of formulae (IIc) and (IId) and/or anionic monomers chosen from maleic anhydride and/or those of formula (IIb):

in which: R1, Z′, x′, R′2 and m′ have the same meaning as that given in claim 1, for formula (IIa); Y is a group chosen from —COOH, —SO₃H, —OSO₃H, —PO₃H₂ and —OPO₃H₂; X′⁺ is a divalent group of formula —N⁺(R₆)(R₇)— with R₆ and R₇ representing, independently of each other, either (i) a hydrogen atom, or (ii) a linear, branched or cyclic, optionally aromatic alkyl group containing from 1 to 25 carbon atoms, possibly comprising 1 to 20 heteroatoms chosen from O, N, S and P; or (iii) R6 and R7 may form with the nitrogen atom a first saturated or unsaturated, optionally aromatic ring comprising in total 5, 6, 7 or 8 atoms, and especially 4, 5, 6 or 7 carbon atoms and/or 2 to 3 heteroatoms chosen from O, S and N; said first ring possibly being fused with one or more other saturated or unsaturated, optionally aromatic rings, each comprising 5, 6, 7 or 8 atoms, and especially 4, 5, 6 or 7 carbon atoms and/or 2 to 3 heteroatoms chosen from O, S and N; Y′⁻ is a group chosen from —COO⁻, —SO₃ ⁻, —OSO₃ ⁻, —PO₃ ²⁻ and —OPO₃ ²⁻; R′3 is a saturated or unsaturated, optionally aromatic, linear, branched or cyclic divalent carbon-based radical of 1 to 30 carbon atoms, possibly comprising 1 to 18 heteroatoms chosen from O, N, S, F, Si and P; n′ is between 1 and 100 and preferably between 1 and 5 inclusive. X″⁺ is a group of formula —N⁺R₆R₇R₈ with R6, R7 and R8 representing, independently of each other, either (i) a hydrogen atom, or (ii) a linear, branched or cyclic, optionally aromatic alkyl group containing from 1 to 18 carbon atoms, possibly comprising 1 to 5 heteroatoms chosen from O, N, S and P; or (iii) R6 and R7 may form with the nitrogen atom a first saturated or unsaturated, optionally aromatic ring comprising in total 5, 6 or 7 atoms, and especially 4, 5 or 6 carbon atoms and/or 2 to 3 heteroatoms chosen from O, S and N; said first ring possibly being fused with one or more other saturated or unsaturated, optionally aromatic rings, each comprising 5, 6 or 7 atoms, and especially 4, 5, 6 or 7 carbon atoms and/or 2 to 3 heteroatoms chosen from O, S and N; especially trimethylammonium; triethylammonium; N,N-dimethyl-N-octylammonium; N,N-dimethyl-N-laurylammonium radicals.
 18. The polymer as claimed in claim 17, in which, in the monomer of formula (IIc) and/or (IId), the radical R′3 is chosen from: an alkylene radical such as methylene, ethylene, propylene, n-butylene, isobutylene, tert-butylene, n-hexylene, n-octylene, n-dodecylene, n-octadecylene, n-tetradecylene or n-docosanylene; a phenylene radical —C₆H₄— (ortho, meta or para), optionally substituted with a C1-C12 alkyl radical optionally comprising 1 to 5 heteroatoms chosen from O, N, S, F, Si and P; or alternatively a benzylene radical —C₆H₄—CH₂—, optionally substituted with a C₁-C₁₂ alkyl radical optionally comprising 1 to 5 heteroatoms chosen from O, N, S, F, Si and P; a radical of formula —CH₂—O—CO—O—, CH₂—CH₂—O—CO—O—, —CH₂—CO—O—, —CH₂—CH₂—CO—O—, —[(CH₂)₅—CO—O]_(n)—, —CH₂—CH(CH₃)—O—, —(CH₂)₂—O—, —CH₂—O—CO—NH—, —CH₂—CH₂—O—CO—NH—; —CH₂—NH—CO—NH— or —CH₂—CH₂—NH—CO—NH—, —CH₂—CHOH—, —CH₂—CH₂—CHOH—, —CH₂—CH₂—CH(NH₂)—, —CH₂—CH(NH₂)—CH₂—CH₂—CH(NHR′)—, —CH₂—CH(NHR′)—, —CH₂—CH₂—CH(NR′R″)—, —CH₂—CH(NR′R″)—, —CH₂—CH₂—CH₂—NR′—, —CH₂—CH₂—CH₂—O—; —[CH₂—CH₂—O]_(n)— and —[CH₂—CH(CH₃)—O]_(n)—, —CH₂—CH₂—CHR′—O— with R′ and R″ representing a linear or branched C1-C22 alkyl optionally comprising 1 to 12 heteroatoms chosen from O, N, S, F, Si and P; or a mixture of these radicals.
 19. The polymer as claimed in either of claims 17 and 18, in which the anionic monomers are chosen from maleic anhydride, acrylic acid, methacrylic acid, crotonic acid, itaconic acid, fumaric acid, maleic acid, 2-carboxyethyl acrylate (CH₂═CH—C(O)—O— (CH₂)₂—COOH); styrenesulfonic acid, 2-acrylamido-2-methyl-propanesulfonic acid, vinylbenzoic acid, vinylphosphoric acid and sulfopropyl (meth)acrylate, and salts thereof.
 20. The polymer as claimed in one of claims 17 to 19, in which the monomers of formula (IIc) or (IId) are chosen from N,N-dimethyl-N-(2-methacryloyloxyethyl)-N-(3-sulfopropyl)ammonium betaine, N,N-dimethyl-N-(3-methacrylamidopropyl)-N-(3-sulfopropyl)ammonium betaine, 1-(3-sulfopropyl)-2-vinylpyridinium betaine and 2-methacryloyloxyethylphosphorylcholine.
 21. The polymer as claimed in one of claims 17 to 20, in which said additional ionic monomers are present in a proportion of from 5% to 40% by weight, especially from 10% to 30% by weight and preferably from 15% to 25% by weight relative to the weight of the “additional cationic+ionic monomers” mixture.
 22. The polymer as claimed in one of claims 17 to 21, in which said ionic monomers are present in a proportion of from 20% to 90% by weight, especially from 40% to 80% by weight and preferably from 50% to 70% by weight relative to the weight of the final polymer.
 23. The polymer as claimed in one of the preceding claims, also comprising at least one additional nonionic hydrophilic monomer chosen from those of formula (III), alone or as a mixture:

in which: R′₁ is hydrogen or —CH₃; Z″ is a divalent group chosen from —COO—, —CONH—, —CONCH₃—, —OCO—, —SO₂, —CO—O—CO—, —CO—CH₂—CO— and —O—; preferably COO and CONH; x″ is 0 or 1; R″ is a saturated or unsaturated, optionally aromatic, linear, branched or cyclic carbon-based radical of 1 to 30 carbon atoms, possibly comprising 1 to 18 heteroatoms chosen from O, N, S, F, Si and P; especially methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, phenyl, benzyl or a radical of formula —CH₂—CH₂—CH₂OH, —CH₂—CH₂—OH, —CH₂—CH₂—CH₂OH or furfuryl.
 24. The polymer as claimed in claim 23, in which the additional nonionic hydrophilic monomer is chosen from: methyl methacrylate, methyl acrylate, ethyl meth-acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, tetrahydrofurfuryl methacrylate, tetrahydro-furfuryl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, ethoxyethyl methacrylate, ethoxyethyl acrylate, N-isopropylacrylamide, N-iso-propylmethacrylamide, N,N-dimethylacrylamide, N,N-di-methylmethacrylamide, vinyl acetate, methyl vinyl ether, ethyl vinyl ether, vinylpyrrolidone, vinyl-caprolactam, N-vinylacetamide and hydroxypropyl acrylate; N-vinyllactam, acrylamide, N-methyl-acrylamide, N,N-dimethylacrylamide, N-methyl-N-vinyl-acetamide, N-vinylformamide, N-methyl-N-vinylformamide, vinyl alcohol (copolymerized in the form of vinyl acetate and then hydrolyzed).
 25. The polymer as claimed in either of claims 23 and 24, in which the additional nonionic hydrophilic monomer, alone or as a mixture, is present in an amount of from 0.1% to 35% by weight, preferably from 1% to 25% by weight, for example from 3% to 15% by weight, or even from 5% to 9.5% by weight, relative to the total weight of the polymer.
 26. The polymer as claimed in one of the preceding claims, in which the neutralizer is chosen from linear, branched or cyclic aliphatic acids and/or unsaturated or aromatic acids, and may especially contain 1 to 1000 carbon atoms and especially 2 to 500 carbon atoms; containing at least one acid function in the Brönsted sense, and especially one or more carboxylic, sulfonic and/or phosphonic acid groups; and also possibly comprising one or more heteroatoms chosen from O, N, Si, F and P, for example in the form of hydroxyl groups.
 27. The polymer as claimed in one of the preceding claims, in which the neutralizer is chosen, alone or as a mixture, from: linear, branched or cyclic, saturated or unsaturated, optionally aromatic fatty acids containing 6 to 32 and especially 8 to 28 carbon atoms, and comprising at least one COOH or sulfonic acid (—SO₃H) function; linear, branched or cyclic, saturated or unsaturated, optionally aromatic hydroxy acids, especially α-hydroxy acids, containing 6 to 32 and especially 8 to 28 carbon atoms, and comprising at least one COOH or sulfonic acid (—SO₃H) function; alkylbenzenesulfonic acids, in which the alkyl group may contain from 4 to 30 and especially from 6 to 24 carbon atoms; amphoteric neutralizers, especially of the alkyl-betaine or alkylamidopropylbetaine type, in which the alkyl group may contain 4 to 30 and especially 6 to 24 carbon atoms; in particular cocoamidopropylbetaine.
 28. The polymer as claimed in one of the preceding claims, in which the neutralizer is chosen from α-hydroxyethanoic acid, α-hydroxyoctanoic acid, α-hydroxycaprylic acid, ascorbic acid, acetic acid, benzoic acid, behenic acid, capric acid, citric acid, caproic acid, caprylic acid, dodecylbenzenesulfonic acid, 2-ethylcaproic acid, folic acid, fumaric acid, galactaric acid, gluconic acid, glycolic acid, 2-hexadecyleicosanoic acid, hydroxycaproic acid, 12-hydroxystearic acid, isolauric acid (or 2-butyloctanoic acid), isomyristic acid (or 2-hexyloctanoic acid), isoarachidic acid (or 2-octyldodecanoic acid), isolignoceric acid (or 2-decyltetradecanoic acid), lactic acid, lauric acid, malic acid, myristic acid, oleic acid, palmitic acid, propionic acid, sebacic acid, stearic acid, tartaric acid, terephthalic acid, trimesic acid, undecylenic acid, propylbetaine, cocoamidopropylbetaine, and betaine hydrochloride of formula [(CH₃ ⁻)₃N+CH₂CO₂H.Cl—], and mixtures thereof.
 29. The polymer as claimed in one of the preceding claims, in which the neutralizer is chosen from caproic acid, 2-ethylcaproic acid, oleic acid, behenic acid, stearic acid, acetic acid, citric acid, tartaric acid, betaine hydrochloride and/or gluconic acid, and preferentially betaine hydrochloride and/or behenic acid.
 30. The polymer as claimed in one of the preceding claims, in which the neutralizer, alone or as a mixture, is added in an amount of from 0.01% to 3 molar equivalents, especially 0.05 to 2.5 or even 0.1 to 2 molar equivalents relative to the total amine functions of the polymer or of the monomers.
 31. The polymer as claimed in claim 30, in which the neutralizer, alone or as a mixture, is added in an amount of from 0.01 to 0.99 molar equivalents, especially 0.05 to 0.9 or even 0.1 to 0.8 molar equivalents relative to the total amine functions of the polymer or of the monomers.
 32. The polymer as claimed in claim 30, in which the neutralizer, alone or as a mixture, is added in an amount of from 1.01 to 3 molar equivalents, especially 1.2 to 2.5 or even 1.5 to 2 molar equivalents relative to the total amine functions of the polymer or of the monomers.
 33. The polymer as claimed in claim 30, in which the neutralizer, alone or as a mixture, is added in an amount of 1 molar equivalent relative to the total amine functions of the polymer or of the monomers.
 34. The polymer as claimed in one of the preceding claims, with a weight-average molecular mass (Mw) of between 500 and 5000000, especially between 1000 and 3000000 and even more preferentially between 2000 and 2000000, or even 4000 and 500000, inter alia between 7000 and 400000, better still between 20000 and 350000 and even better between 150000 and
 300000. 35. The polymer as claimed in one of the preceding claims, characterized in that it is conveyable in aqueous medium, preferably water-soluble or water-dispersible.
 36. The polymer as claimed in one of the preceding claims, characterized in that it has a viscosity in water of between 1 and 1000 mPa·s, preferably between 1.5 and 750 mPa·s and better still between 2 and 500 mPa·s, measured at 25° C., using a Brookfield viscometer, for a solution containing 15% by weight of the polymer in water or methyl ethyl ketone, at 25° C., with a No. 1 spindle of needle type; for a measuring time of 5 minutes, at a speed of between 0.1 and 6 rpm.
 37. The polymer as claimed in one of the preceding claims, characterized in that it has a glass transition temperature (Tg) of between −150° C. and 20° C., especially −120° C. and 10° C. and better still between −100° C. and 0° C.
 38. The polymer as claimed in one of the preceding claims, characterized in that it has a water uptake of between 3% and 150% by weight, preferably between 4% and 100% by weight and especially between 5% and 50% by weight, at 75% relative humidity (75% RH); and/or in that it has a water uptake of between 3% and 200% by weight, preferably between 55% and 150% by weight, especially between 60% and 120% by weight or even between 70% and 100% by weight, at 85% relative humidity (85% RH).
 39. The polymer as claimed in one of the preceding claims, in which: the monomer of formula (I), alone or as a mixture, is present in a proportion of from 10% to 80% by weight, especially from 20% to 60% by weight and preferably from 30% to 50% by weight relative to the weight of the final polymer, and is chosen, alone or as a mixture, from poly(ethylene glycol) (meth)acrylates, preferably those with a molecular weight of between 350 and 13000 g/mol and especially between 500 and 8000 g/mol; and the “essentially cationic” monomer is present in a proportion of from 20% to 90% by weight, especially from 40% to 80% by weight and preferably from 50% to 70% by weight relative to the weight of the final polymer and is chosen, alone or as a mixture, from dimethylaminopropyl(meth)acrylamide, dimethylamino-ethyl(meth)acrylamide, diethylaminoethyl (meth)acryl-ate, dimethylaminoethyl (meth)acrylate, vinylimidazole, vinylpyridine and morpholinoethyl (meth)acrylate; and the polymer is neutralized with a neutralizer chosen from 2-ethylcaproic acid, oleic acid, behenic acid, stearic acid, acetic acid, citric acid, tartaric acid, betaine hydrochloride and/or gluconic acid, and preferentially behenic acid and/or betaine hydrochloride.
 40. The polymer as claimed in one of the preceding claims, in which: the monomer of formula (I), alone or as a mixture, is present in a proportion of from 10% to 80% by weight, especially from 20% to 60% by weight and preferably from 30% to 50% by weight and is chosen, alone or as a mixture from poly(ethylene glycol) (meth)acrylates, preferably those with a molecular weight of between 350 and 13000 g/mol and especially between 500 and 8000 g/mol; and the “essentially cationic” monomer is present in a proportion of from 20% to 90% by weight, especially from 40% to 80% by weight and preferably from 50% to 70% by weight relative to the weight of the final polymer and is chosen, alone or as a mixture, from dimethylaminopropyl(meth)acrylamide, and the polymer is neutralized with a neutralizer chosen from behenic acid and/or betaine hydrochloride.
 41. A cosmetic or pharmaceutical composition comprising, in a physiologically acceptable medium, especially a cosmetically or pharmaceutically acceptable medium, at least one polymer as defined in one of claims 1 to
 40. 42. The composition as claimed in claim 41, comprising a solution in water or in an organic solvent, or alternatively an aqueous or organic dispersion of the polymer as claimed in one of claims 1 to
 40. 43. The composition as claimed in either of claims 41 and 42, in which the polymer is present in a proportion of from 0.01% to 50% by weight, especially from 0.1% to 30% by weight or even from 0.3% to 10% by weight and better still from 1% to 3% by weight of solids relative to the total weight of the composition.
 44. The composition as claimed in one of claims 41 to 43, in which the physiologically acceptable medium comprises at least one constituent chosen from water; hydrophilic organic solvents, for instance alcohols, especially linear or branched C₁-C₆ monoalcohols and polyols and glycol ethers, especially C₂ glycol ethers and hydrophilic C₂-C₄ aldehydes; waxes, pasty fatty substances, gums and mixtures thereof, of animal, plant, mineral or synthetic origin; lipophilic organic solvents; oils of animal, plant, mineral or synthetic origin; synthetic esters and ethers; pentaerythritol esters; fatty alcohols containing from 12 to 26 carbon atoms; partially hydrocarbon-based and/or silicone-based fluoro oils; volatile or nonvolatile, linear or cyclic silicone oils, which are liquid or pasty at room temperature; pigments, nacres, fillers, water-soluble dyes and liposoluble dyes; polymers; auxiliary film-forming agents; surfactants; vitamins, fragrances, nacreous agents, thickeners, gelling agents, trace elements, softeners, sequestrants, fragrances, acidifying or basifying agents, preserving agents, sunscreens, antioxidants, hair-loss counteractants, antidandruff agents, propellants and ceramides; mixtures thereof.
 45. The composition as claimed in one of claims 41 to 44, which is in the form of a suspension, a dispersion especially of oil in water by means of vesicles; an optionally thickened or even gelled oily solution; an oil-in-water, water-in-oil or multiple emulsion; a gel or a mousse; an oily or emulsified gel; a dispersion of vesicles, especially lipid vesicles; a two-phase or multiphase lotion; a spray; a lotion, a cream, a pomade, a soft paste, an ointment, a cast or molded solid especially in stick or dish form, or alternatively a compacted solid.
 46. The composition as claimed in one of claims 41 to 45, which is in the form of a care and/or makeup product for bodily or facial skin, the lips and the hair, an antisun or self-tanning product or a haircare product.
 47. The composition as claimed in one of claims 41 to 46, which is in the form of a hair composition, especially for holding the hairstyle or shaping the hair, for example in the form of shampoos, hairsetting gels or lotions, blow-drying lotions, fixing and styling compositions such as lacquers or sprays; rinse-out or leave-in hair conditioners, compositions for permanent-waving, relaxing, dyeing or bleaching the hair, or alternatively in the form of rinse-out compositions, to be applied before or after dyeing, bleaching, permanent-waving or relaxing the hair or between the two steps of a permanent-waving or hair-relaxing operation.
 48. A cosmetic process for treating keratin materials such as bodily or facial skin, the nails, bodily hair, head hair and/or the eyelashes, characterized in that it consists in applying to the keratin materials a cosmetic composition as defined in one of claims 41 to 47 and then optionally rinsing with water.
 48. A cosmetic process for holding the hairstyle; for treating, caring for and/or washing and/or removing makeup from bodily or facial skin, the nails, bodily hair, head hair and/or the eyelashes, characterized in that it consists in applying to the keratin materials a cosmetic composition as defined in one of claims 41 to 47 and then optionally rinsing with water.
 50. A process for preparing an ethylenic copolymer as defined in one of claims 1 to 40, in which the amine units of the monomers included in the constitution of the polymer, in particular the amine units of the cationic monomers of formula (IIa), are neutralized before the polymerization, and the neutralized monomers are then copolymerized in order to obtain the desired copolymer.
 51. A process for preparing an ethylenic copolymer as defined in one of claims 1 to 40, in which the non-neutralized monomers included in the constitution of the polymer are polymerized, and said copolymer is then neutralized after its formation. 